<?xml version="1.0" encoding="us-ascii"?>
<!-- DFIN ActiveDisclosure(SM) XBRL Schema Document - http://www.dfinsolutions.com/ -->
<!-- Creation Date      : 2021-02-23T02:41:58.3167834+00:00 -->
<!-- Version            : 5.0.1.571 -->
<!-- Package ID         : b969c44e66bc471e97ed9b15572e68b1 -->
<!-- Copyright (c) 2021 Donnelley Financial Solutions, Inc. All Rights Reserved. -->
<xsd:schema xmlns:nonnum="http://www.xbrl.org/dtr/type/non-numeric" xmlns:dei="http://xbrl.sec.gov/dei/2020-01-31" xmlns:num="http://www.xbrl.org/dtr/type/numeric" xmlns:us-types="http://fasb.org/us-types/2020-01-31" xmlns:stpr="http://xbrl.sec.gov/stpr/2018-01-31" xmlns:srt-types="http://fasb.org/srt-types/2020-01-31" xmlns:sic="http://xbrl.sec.gov/sic/2020-01-31" xmlns:wltw="http://www.willistowerswatson.com/20201231" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:srt="http://fasb.org/srt/2020-01-31" xmlns:us-gaap="http://fasb.org/us-gaap/2020-01-31" xmlns:naics="http://xbrl.sec.gov/naics/2017-01-31" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:country="http://xbrl.sec.gov/country/2020-01-31" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:currency="http://xbrl.sec.gov/currency/2020-01-31" xmlns:exch="http://xbrl.sec.gov/exch/2020-01-31" attributeFormDefault="unqualified" elementFormDefault="qualified" targetNamespace="http://www.willistowerswatson.com/20201231" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <xsd:import schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd" namespace="http://www.xbrl.org/2003/instance" />
  <xsd:import schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" namespace="http://www.xbrl.org/2003/linkbase" />
  <xsd:import schemaLocation="http://www.xbrl.org/2005/xbrldt-2005.xsd" namespace="http://xbrl.org/2005/xbrldt" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd" namespace="http://xbrl.sec.gov/country/2020-01-31" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/currency/2020/currency-2020-01-31.xsd" namespace="http://xbrl.sec.gov/currency/2020-01-31" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd" namespace="http://xbrl.sec.gov/dei/2020-01-31" />
  <xsd:import schemaLocation="http://www.xbrl.org/dtr/type/nonNumeric-2009-12-16.xsd" namespace="http://www.xbrl.org/dtr/type/non-numeric" />
  <xsd:import schemaLocation="http://www.xbrl.org/dtr/type/numeric-2009-12-16.xsd" namespace="http://www.xbrl.org/dtr/type/numeric" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/exch/2020/exch-2020-01-31.xsd" namespace="http://xbrl.sec.gov/exch/2020-01-31" />
  <xsd:import schemaLocation="http://www.xbrl.org/lrr/arcrole/factExplanatory-2009-12-16.xsd" namespace="http://www.xbrl.org/2009/arcrole/fact-explanatoryFact" />
  <xsd:import schemaLocation="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd" namespace="http://www.xbrl.org/2009/role/negated" />
  <xsd:import schemaLocation="http://www.xbrl.org/lrr/role/net-2009-12-16.xsd" namespace="http://www.xbrl.org/2009/role/net" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/naics/2017/naics-2017-01-31.xsd" namespace="http://xbrl.sec.gov/naics/2017-01-31" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/sic/2020/sic-2020-01-31.xsd" namespace="http://xbrl.sec.gov/sic/2020-01-31" />
  <xsd:import schemaLocation="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd" namespace="http://fasb.org/srt/2020-01-31" />
  <xsd:import schemaLocation="http://xbrl.fasb.org/srt/2020/elts/srt-roles-2020-01-31.xsd" namespace="http://fasb.org/srt-roles/2020-01-31" />
  <xsd:import schemaLocation="http://xbrl.fasb.org/srt/2020/elts/srt-types-2020-01-31.xsd" namespace="http://fasb.org/srt-types/2020-01-31" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/stpr/2018/stpr-2018-01-31.xsd" namespace="http://xbrl.sec.gov/stpr/2018-01-31" />
  <xsd:import schemaLocation="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd" namespace="http://fasb.org/us-gaap/2020-01-31" />
  <xsd:import schemaLocation="http://xbrl.fasb.org/us-gaap/2020/elts/us-roles-2020-01-31.xsd" namespace="http://fasb.org/us-roles/2020-01-31" />
  <xsd:import schemaLocation="http://xbrl.fasb.org/us-gaap/2020/elts/us-types-2020-01-31.xsd" namespace="http://fasb.org/us-types/2020-01-31" />
  <xsd:annotation>
    <xsd:appinfo>
      <link:roleType id="TemplateLink" roleURI="http://www.willistowerswatson.com/20201231/role/TemplateLink" xmlns:link="http://www.xbrl.org/2003/linkbase">
        <link:definition>00000 - Document - Template Link</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="wltw-20201231_cal.xml" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" xlink:title="Calculation Links, all" xlink:type="simple" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" />
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="wltw-20201231_def.xml" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:title="Definition Links, all" xlink:type="simple" />
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="wltw-20201231_lab.xml" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:title="Label Links, all" xlink:type="simple" />
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="wltw-20201231_pre.xml" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:title="Presentation Links, all" xlink:type="simple" />
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DocumentDocumentAndEntityInformation" id="Role_DocumentDocumentAndEntityInformation">
        <link:definition>100000 - Document - Document and Entity Information</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/StatementConsolidatedStatementsOfComprehensiveIncome" id="Role_StatementConsolidatedStatementsOfComprehensiveIncome">
        <link:definition>100010 - Statement - Consolidated Statements of Comprehensive Income</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/StatementConsolidatedBalanceSheets" id="Role_StatementConsolidatedBalanceSheets">
        <link:definition>100020 - Statement - Consolidated Balance Sheets</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/StatementConsolidatedBalanceSheetsParenthetical" id="Role_StatementConsolidatedBalanceSheetsParenthetical">
        <link:definition>100030 - Statement - Consolidated Balance Sheets (Parenthetical)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/StatementConsolidatedStatementsOfCashFlows" id="Role_StatementConsolidatedStatementsOfCashFlows">
        <link:definition>100040 - Statement - Consolidated Statements of Cash Flows</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/StatementConsolidatedStatementsOfCashFlowsParenthetical" id="Role_StatementConsolidatedStatementsOfCashFlowsParenthetical">
        <link:definition>100050 - Statement - Consolidated Statements of Cash Flows (Parenthetical)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/StatementConsolidatedStatementsOfChangesInEquity" id="Role_StatementConsolidatedStatementsOfChangesInEquity">
        <link:definition>100060 - Statement - Consolidated Statements of Changes in Equity</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/StatementConsolidatedStatementsOfChangesInEquityParenthetical" id="Role_StatementConsolidatedStatementsOfChangesInEquityParenthetical">
        <link:definition>100070 - Statement - Consolidated Statements of Changes in Equity (Parenthetical)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureNatureOfOperations" id="Role_DisclosureNatureOfOperations">
        <link:definition>100080 - Disclosure - Nature of Operations</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureBasisOfPresentationSignificantAccountingPoliciesAndRecentAccountingPronouncements" id="Role_DisclosureBasisOfPresentationSignificantAccountingPoliciesAndRecentAccountingPronouncements">
        <link:definition>100090 - Disclosure - Basis of Presentation, Significant Accounting Policies and Recent Accounting Pronouncements</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureAcquisitionsAndDivestitures" id="Role_DisclosureAcquisitionsAndDivestitures">
        <link:definition>100100 - Disclosure - Acquisitions and Divestitures</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRevenue" id="Role_DisclosureRevenue">
        <link:definition>100110 - Disclosure - Revenue</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureSegmentInformation" id="Role_DisclosureSegmentInformation">
        <link:definition>100120 - Disclosure - Segment Information</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureIncomeTaxes" id="Role_DisclosureIncomeTaxes">
        <link:definition>100130 - Disclosure - Income Taxes</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureFixedAssets" id="Role_DisclosureFixedAssets">
        <link:definition>100140 - Disclosure - Fixed Assets</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureGoodwillAndOtherIntangibleAssets" id="Role_DisclosureGoodwillAndOtherIntangibleAssets">
        <link:definition>100150 - Disclosure - Goodwill and Other Intangible Assets</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureDerivativeFinancialInstruments" id="Role_DisclosureDerivativeFinancialInstruments">
        <link:definition>100160 - Disclosure - Derivative Financial Instruments</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureDebt" id="Role_DisclosureDebt">
        <link:definition>100170 - Disclosure - Debt</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureFairValueMeasurements" id="Role_DisclosureFairValueMeasurements">
        <link:definition>100180 - Disclosure - Fair Value Measurements</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRetirementBenefits" id="Role_DisclosureRetirementBenefits">
        <link:definition>100190 - Disclosure - Retirement Benefits</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureLeases" id="Role_DisclosureLeases">
        <link:definition>100200 - Disclosure - Leases</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureCommitmentsAndContingencies" id="Role_DisclosureCommitmentsAndContingencies">
        <link:definition>100210 - Disclosure - Commitments and Contingencies</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureSupplementaryInformationForCertainBalanceSheetAccounts" id="Role_DisclosureSupplementaryInformationForCertainBalanceSheetAccounts">
        <link:definition>100220 - Disclosure - Supplementary Information for Certain Balance Sheet Accounts</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureOtherIncomeNet" id="Role_DisclosureOtherIncomeNet">
        <link:definition>100230 - Disclosure - Other Income, Net</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureAccumulatedOtherComprehensiveLoss" id="Role_DisclosureAccumulatedOtherComprehensiveLoss">
        <link:definition>100240 - Disclosure - Accumulated Other Comprehensive Loss</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureShareBasedCompensation" id="Role_DisclosureShareBasedCompensation">
        <link:definition>100250 - Disclosure - Share-Based Compensation</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureEarningsPerShare" id="Role_DisclosureEarningsPerShare">
        <link:definition>100260 - Disclosure - Earnings Per Share</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureSupplementalDisclosuresOfCashFlowInformation" id="Role_DisclosureSupplementalDisclosuresOfCashFlowInformation">
        <link:definition>100270 - Disclosure - Supplemental Disclosures of Cash Flow Information</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureBasisOfPresentationSignificantAccountingPoliciesAndRecentAccountingPronouncementsPolicies" id="Role_DisclosureBasisOfPresentationSignificantAccountingPoliciesAndRecentAccountingPronouncementsPolicies">
        <link:definition>100280 - Disclosure - Basis of Presentation, Significant Accounting Policies and Recent Accounting Pronouncements (Policies)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureBasisOfPresentationSignificantAccountingPoliciesAndRecentAccountingPronouncementsTables" id="Role_DisclosureBasisOfPresentationSignificantAccountingPoliciesAndRecentAccountingPronouncementsTables">
        <link:definition>100290 - Disclosure - Basis of Presentation, Significant Accounting Policies and Recent Accounting Pronouncements (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureAcquisitionsAndDivesturesTables" id="Role_DisclosureAcquisitionsAndDivesturesTables">
        <link:definition>100300 - Disclosure - Acquisitions and Divestures (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRevenueTables" id="Role_DisclosureRevenueTables">
        <link:definition>100310 - Disclosure - Revenue (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureSegmentInformationTables" id="Role_DisclosureSegmentInformationTables">
        <link:definition>100320 - Disclosure - Segment Information (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureIncomeTaxesTables" id="Role_DisclosureIncomeTaxesTables">
        <link:definition>100330 - Disclosure - Income Taxes (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureFixedAssetsTables" id="Role_DisclosureFixedAssetsTables">
        <link:definition>100340 - Disclosure - Fixed Assets (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureGoodwillAndOtherIntangibleAssetsTables" id="Role_DisclosureGoodwillAndOtherIntangibleAssetsTables">
        <link:definition>100350 - Disclosure - Goodwill and Other Intangible Assets (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureDerivativeFinancialInstrumentsTables" id="Role_DisclosureDerivativeFinancialInstrumentsTables">
        <link:definition>100360 - Disclosure - Derivative Financial Instruments (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureDebtTables" id="Role_DisclosureDebtTables">
        <link:definition>100370 - Disclosure - Debt (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureFairValueMeasurementsTables" id="Role_DisclosureFairValueMeasurementsTables">
        <link:definition>100380 - Disclosure - Fair Value Measurements (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRetirementBenefitsTables" id="Role_DisclosureRetirementBenefitsTables">
        <link:definition>100390 - Disclosure - Retirement Benefits (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureLeasesTables" id="Role_DisclosureLeasesTables">
        <link:definition>100400 - Disclosure - Leases (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureSupplementaryInformationForCertainBalanceSheetAccountsTables" id="Role_DisclosureSupplementaryInformationForCertainBalanceSheetAccountsTables">
        <link:definition>100410 - Disclosure - Supplementary Information for Certain Balance Sheet Accounts (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureOtherIncomeNetTables" id="Role_DisclosureOtherIncomeNetTables">
        <link:definition>100420 - Disclosure - Other Income, Net (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureAccumulatedOtherComprehensiveLossTables" id="Role_DisclosureAccumulatedOtherComprehensiveLossTables">
        <link:definition>100430 - Disclosure - Accumulated Other Comprehensive Loss (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureShareBasedCompensationTables" id="Role_DisclosureShareBasedCompensationTables">
        <link:definition>100440 - Disclosure - Share-Based Compensation (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureEarningsPerShareTables" id="Role_DisclosureEarningsPerShareTables">
        <link:definition>100450 - Disclosure - Earnings Per Share (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureSupplementalDisclosuresOfCashFlowInformationTables" id="Role_DisclosureSupplementalDisclosuresOfCashFlowInformationTables">
        <link:definition>100460 - Disclosure - Supplemental Disclosures of Cash Flow Information (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureNatureOfOperationsDetails" id="Role_DisclosureNatureOfOperationsDetails">
        <link:definition>100470 - Disclosure - Nature of Operations (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureBasisOfPresentationSignificantAccountingPoliciesAndRecentAccountingPronouncementsNarrativeDetails" id="Role_DisclosureBasisOfPresentationSignificantAccountingPoliciesAndRecentAccountingPronouncementsNarrativeDetails">
        <link:definition>100480 - Disclosure - Basis of Presentation, Significant Accounting Policies and Recent Accounting Pronouncements - Narrative (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureBasisOfPresentationSignificantAccountingPoliciesAndRecentAccountingPronouncementsScheduleOfAcquiredIntangibleAssetsAmortizedDetails" id="Role_DisclosureBasisOfPresentationSignificantAccountingPoliciesAndRecentAccountingPronouncementsScheduleOfAcquiredIntangibleAssetsAmortizedDetails">
        <link:definition>100490 - Disclosure - Basis of Presentation, Significant Accounting Policies and Recent Accounting Pronouncements - Schedule of Acquired Intangible Assets Amortized (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureAcquisitionsAndDivestituresNarrativeDetails" id="Role_DisclosureAcquisitionsAndDivestituresNarrativeDetails">
        <link:definition>100500 - Disclosure - Acquisitions and Divestitures - Narrative (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureAcquisitionsAndDivestituresSummaryOfFairValuesOfIdentifiableAssetsAcquiredAndLiabilitiesAssumedDetails" id="Role_DisclosureAcquisitionsAndDivestituresSummaryOfFairValuesOfIdentifiableAssetsAcquiredAndLiabilitiesAssumedDetails">
        <link:definition>100510 - Disclosure - Acquisitions and Divestitures - Summary of Fair Values of Identifiable Assets Acquired and Liabilities Assumed (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureAcquisitionsAndDivestituresSummaryOfPreliminaryFairValuesOfIdentifiableAssetsAcquiredAndLiabilitiesAssumedParentheticalDetails" id="Role_DisclosureAcquisitionsAndDivestituresSummaryOfPreliminaryFairValuesOfIdentifiableAssetsAcquiredAndLiabilitiesAssumedParentheticalDetails">
        <link:definition>100520 - Disclosure - Acquisitions and Divestitures - Summary of Preliminary Fair Values of Identifiable Assets Acquired and Liabilities Assumed (Parenthetical) (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureAcquisitionsAndDivestituresMaxMatthiessenDivestitureDetails" id="Role_DisclosureAcquisitionsAndDivestituresMaxMatthiessenDivestitureDetails">
        <link:definition>100530 - Disclosure - Acquisitions and Divestitures - Max Matthiessen Divestiture (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureAcquisitionsAndDivestituresMillerDivestitureDetails" id="Role_DisclosureAcquisitionsAndDivestituresMillerDivestitureDetails">
        <link:definition>100540 - Disclosure - Acquisitions and Divestitures - Miller Divestiture (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRevenueScheduleOfDisaggregationOfRevenueDetails" id="Role_DisclosureRevenueScheduleOfDisaggregationOfRevenueDetails">
        <link:definition>100550 - Disclosure - Revenue - Schedule of Disaggregation of Revenue (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRevenueNarrativeDetails" id="Role_DisclosureRevenueNarrativeDetails">
        <link:definition>100560 - Disclosure - Revenue - Narrative (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRevenueScheduleOfRevenueByGeographyDetail" id="Role_DisclosureRevenueScheduleOfRevenueByGeographyDetail">
        <link:definition>100570 - Disclosure - Revenue - Schedule of Revenue by Geography (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRevenueScheduleOfContractBalancesDetails" id="Role_DisclosureRevenueScheduleOfContractBalancesDetails">
        <link:definition>100580 - Disclosure - Revenue - Schedule of Contract Balances (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRevenueScheduleOfContractBalancesParentheticalDetails" id="Role_DisclosureRevenueScheduleOfContractBalancesParentheticalDetails">
        <link:definition>100590 - Disclosure - Revenue - Schedule of Contract Balances (Parenthetical) (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRevenueScheduleOfChangesInAllowanceForDoubtfulAccountsDetails" id="Role_DisclosureRevenueScheduleOfChangesInAllowanceForDoubtfulAccountsDetails">
        <link:definition>100600 - Disclosure - Revenue - Schedule of Changes in Allowance for Doubtful Accounts (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRevenueScheduleOfRemainingPerformanceObligationsDetails" id="Role_DisclosureRevenueScheduleOfRemainingPerformanceObligationsDetails">
        <link:definition>100610 - Disclosure - Revenue - Schedule of Remaining Performance Obligations (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRevenueScheduleOfRemainingPerformanceObligationsDetailsDefault" id="Role_DisclosureRevenueScheduleOfRemainingPerformanceObligationsDetailsDefault">
        <link:definition>100610 - Disclosure - Revenue - Schedule of Remaining Performance Obligations (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRevenueScheduleOfRemainingPerformanceObligationsDetails1" id="Role_DisclosureRevenueScheduleOfRemainingPerformanceObligationsDetails1">
        <link:definition>100620 - Disclosure - Revenue - Schedule of Remaining Performance Obligations (Details1)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRevenueScheduleOfCapitalizedAndDeferredCostsDetails" id="Role_DisclosureRevenueScheduleOfCapitalizedAndDeferredCostsDetails">
        <link:definition>100630 - Disclosure - Revenue - Schedule of Capitalized and Deferred Costs (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureSegmentInformationNarrativeDetails" id="Role_DisclosureSegmentInformationNarrativeDetails">
        <link:definition>100640 - Disclosure - Segment Information - Narrative (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureSegmentInformationRevenueNetOfReimbursableExpensesOfReportedSegmentsDetails" id="Role_DisclosureSegmentInformationRevenueNetOfReimbursableExpensesOfReportedSegmentsDetails">
        <link:definition>100650 - Disclosure - Segment Information - Revenue (Net of Reimbursable Expenses) of the Reported Segments (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureSegmentInformationReconciliationOfInformationReportedBySegmentToConsolidatedAmountsDetails" id="Role_DisclosureSegmentInformationReconciliationOfInformationReportedBySegmentToConsolidatedAmountsDetails">
        <link:definition>100660 - Disclosure - Segment Information - Reconciliation of Information Reported by Segment to Consolidated Amounts (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureSegmentInformationRevenueAndLongLivedAssetsByGeographicalAreasDetails" id="Role_DisclosureSegmentInformationRevenueAndLongLivedAssetsByGeographicalAreasDetails">
        <link:definition>100670 - Disclosure - Segment Information - Revenue and Long-Lived Assets by Geographical Areas (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureIncomeTaxesNarrativeDetails" id="Role_DisclosureIncomeTaxesNarrativeDetails">
        <link:definition>100680 - Disclosure - Income Taxes - Narrative (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureIncomeTaxesIncomeLossFromOperationsBeforeIncomeTaxesDetails" id="Role_DisclosureIncomeTaxesIncomeLossFromOperationsBeforeIncomeTaxesDetails">
        <link:definition>100690 - Disclosure - Income Taxes - Income (Loss) from Operations Before Income Taxes (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureIncomeTaxesProvisionForBenefitFromIncomeTaxesDetails" id="Role_DisclosureIncomeTaxesProvisionForBenefitFromIncomeTaxesDetails">
        <link:definition>100700 - Disclosure - Income Taxes - (Provision for) Benefit from Income Taxes (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureIncomeTaxesEffectiveTaxRateReconciliationDetails" id="Role_DisclosureIncomeTaxesEffectiveTaxRateReconciliationDetails">
        <link:definition>100710 - Disclosure - Income Taxes - Effective Tax Rate Reconciliation (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureIncomeTaxesDeferredTaxAssetsLiabilitiesDetails" id="Role_DisclosureIncomeTaxesDeferredTaxAssetsLiabilitiesDetails">
        <link:definition>100720 - Disclosure - Income Taxes - Deferred Tax Assets (Liabilities) (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureIncomeTaxesDeferredTaxLiabilitiesBalanceSheetClassificationDetails" id="Role_DisclosureIncomeTaxesDeferredTaxLiabilitiesBalanceSheetClassificationDetails">
        <link:definition>100730 - Disclosure - Income Taxes - Deferred Tax Liabilities, Balance Sheet Classification (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureIncomeTaxesValuationAllowanceDetails" id="Role_DisclosureIncomeTaxesValuationAllowanceDetails">
        <link:definition>100740 - Disclosure - Income Taxes - Valuation Allowance (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureIncomeTaxesUnrecognizedTaxBenefitsDetails" id="Role_DisclosureIncomeTaxesUnrecognizedTaxBenefitsDetails">
        <link:definition>100750 - Disclosure - Income Taxes - Unrecognized Tax Benefits (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureIncomeTaxesSummaryOfTaxYearsThatRemainOpenToTaxExaminationInMajorTaxJurisdictionsDetails" id="Role_DisclosureIncomeTaxesSummaryOfTaxYearsThatRemainOpenToTaxExaminationInMajorTaxJurisdictionsDetails">
        <link:definition>100760 - Disclosure - Income Taxes - Summary of Tax Years that Remain Open to Tax Examination in Major Tax Jurisdictions (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureFixedAssetsComponentsOfFixedAssetsDetails" id="Role_DisclosureFixedAssetsComponentsOfFixedAssetsDetails">
        <link:definition>100770 - Disclosure - Fixed Assets - Components of Fixed Assets (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureFixedAssetsComponentsOfFixedAssetsParentheticalDetails" id="Role_DisclosureFixedAssetsComponentsOfFixedAssetsParentheticalDetails">
        <link:definition>100780 - Disclosure - Fixed Assets - Components of Fixed Assets (Parenthetical) (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureFixedAssetsAssetsHeldUnderFinanceLeasesDetails" id="Role_DisclosureFixedAssetsAssetsHeldUnderFinanceLeasesDetails">
        <link:definition>100790 - Disclosure - Fixed Assets - Assets Held Under Finance Leases (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureGoodwillAndOtherIntangibleAssetsComponentsOfGoodwillDetails" id="Role_DisclosureGoodwillAndOtherIntangibleAssetsComponentsOfGoodwillDetails">
        <link:definition>100800 - Disclosure - Goodwill and Other Intangible Assets - Components of Goodwill (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureGoodwillAndOtherIntangibleAssetsChangesInNetCarryingAmountOfComponentsOfFiniteLivedIntangibleAssetsDetails" id="Role_DisclosureGoodwillAndOtherIntangibleAssetsChangesInNetCarryingAmountOfComponentsOfFiniteLivedIntangibleAssetsDetails">
        <link:definition>100810 - Disclosure - Goodwill and Other Intangible Assets - Changes in the Net Carrying Amount of the Components of Finite-Lived Intangible Assets (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureGoodwillAndOtherIntangibleAssetsChangesInNetCarryingAmountOfComponentsOfFiniteLivedIntangibleAssetsParentheticalDetails" id="Role_DisclosureGoodwillAndOtherIntangibleAssetsChangesInNetCarryingAmountOfComponentsOfFiniteLivedIntangibleAssetsParentheticalDetails">
        <link:definition>100820 - Disclosure - Goodwill and Other Intangible Assets - Changes in the Net Carrying Amount of the Components of Finite-Lived Intangible Assets (Parenthetical) (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureGoodwillAndOtherIntangibleAssetsNarrativeDetails" id="Role_DisclosureGoodwillAndOtherIntangibleAssetsNarrativeDetails">
        <link:definition>100830 - Disclosure - Goodwill and Other Intangible Assets - Narrative (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureGoodwillAndOtherIntangibleAssetsScheduleOfFutureEstimatedAmortizationExpenseForAmortizableIntangibleAssetsDetails" id="Role_DisclosureGoodwillAndOtherIntangibleAssetsScheduleOfFutureEstimatedAmortizationExpenseForAmortizableIntangibleAssetsDetails">
        <link:definition>100840 - Disclosure - Goodwill and Other Intangible Assets - Schedule of Future Estimated Amortization Expense for Amortizable Intangible Assets (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureDerivativeFinancialInstrumentsNarrativeDetails" id="Role_DisclosureDerivativeFinancialInstrumentsNarrativeDetails">
        <link:definition>100850 - Disclosure - Derivative Financial Instruments - Narrative (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfDerivativeInstrumentsDesignatedAsHedgingInstrumentEffectOnCondensedConsolidatedStatementsOfComprehensiveIncomeDetails" id="Role_DisclosureDerivativeFinancialInstrumentsScheduleOfDerivativeInstrumentsDesignatedAsHedgingInstrumentEffectOnCondensedConsolidatedStatementsOfComprehensiveIncomeDetails">
        <link:definition>100860 - Disclosure - Derivative Financial Instruments - Schedule of Derivative Instruments Designated As Hedging Instrument Effect on Condensed Consolidated Statements of Comprehensive Income (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfDerivativeInstrumentsEffectOnCondensedConsolidatedStatementsOfComprehensiveIncomeDetails" id="Role_DisclosureDerivativeFinancialInstrumentsScheduleOfDerivativeInstrumentsEffectOnCondensedConsolidatedStatementsOfComprehensiveIncomeDetails">
        <link:definition>100870 - Disclosure - Derivative Financial Instruments - Schedule Of Derivative Instruments, Effect on Condensed Consolidated Statements of Comprehensive Income (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureDebtScheduleOfCurrentAndLongTermDebtDetails" id="Role_DisclosureDebtScheduleOfCurrentAndLongTermDebtDetails">
        <link:definition>100880 - Disclosure - Debt - Schedule of Current and Long-term Debt (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureDebtNarrativeDetails" id="Role_DisclosureDebtNarrativeDetails">
        <link:definition>100890 - Disclosure - Debt - Narrative (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureDebtMaturitiesOfLongTermDebtDetails" id="Role_DisclosureDebtMaturitiesOfLongTermDebtDetails">
        <link:definition>100900 - Disclosure - Debt - Maturities of Long Term Debt (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureDebtInterestExpenseDetails" id="Role_DisclosureDebtInterestExpenseDetails">
        <link:definition>100910 - Disclosure - Debt - Interest Expense (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureFairValueMeasurementsScheduleOfAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasisDetails" id="Role_DisclosureFairValueMeasurementsScheduleOfAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasisDetails">
        <link:definition>100920 - Disclosure - Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureFairValueMeasurementsFairValueLiabilitiesMeasuredUsingSignificantUnobservableInputsLevel3Details" id="Role_DisclosureFairValueMeasurementsFairValueLiabilitiesMeasuredUsingSignificantUnobservableInputsLevel3Details">
        <link:definition>100930 - Disclosure - Fair Value Measurements - Fair Value Liabilities Measured Using Significant Unobservable Inputs Level 3 (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureFairValueMeasurementsNarrativeDetails" id="Role_DisclosureFairValueMeasurementsNarrativeDetails">
        <link:definition>100940 - Disclosure - Fair Value Measurements - Narrative (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureFairValueMeasurementsScheduleOfAssetsAndLiabilitiesWhoseCarryingValuesDifferFromFairValueAndAreNotMeasuredOnRecurringBasisDetails" id="Role_DisclosureFairValueMeasurementsScheduleOfAssetsAndLiabilitiesWhoseCarryingValuesDifferFromFairValueAndAreNotMeasuredOnRecurringBasisDetails">
        <link:definition>100950 - Disclosure - Fair Value Measurements - Schedule of Assets and Liabilities Whose Carrying Values Differ From the Fair Value and are Not Measured on a Recurring Basis (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRetirementBenefitsNarrativeDetails" id="Role_DisclosureRetirementBenefitsNarrativeDetails">
        <link:definition>100960 - Disclosure - Retirement Benefits - Narrative (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRetirementBenefitsChangeInBenefitObligationAndPlanAssetsDetails" id="Role_DisclosureRetirementBenefitsChangeInBenefitObligationAndPlanAssetsDetails">
        <link:definition>100970 - Disclosure - Retirement Benefits - Change in Benefit Obligation and Plan Assets (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRetirementBenefitsAmountsRecognizedInOtherComprehensiveIncomeLossDetails" id="Role_DisclosureRetirementBenefitsAmountsRecognizedInOtherComprehensiveIncomeLossDetails">
        <link:definition>100980 - Disclosure - Retirement Benefits - Amounts Recognized in Other Comprehensive Income (Loss) (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRetirementBenefitsBenefitObligationInExcessOfPlanAssetsDetails" id="Role_DisclosureRetirementBenefitsBenefitObligationInExcessOfPlanAssetsDetails">
        <link:definition>100990 - Disclosure - Retirement Benefits - Benefit Obligation In Excess Of Plan Assets (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRetirementBenefitsAccumulatedBenefitObligationInExcessOfPlanAssetsDetails" id="Role_DisclosureRetirementBenefitsAccumulatedBenefitObligationInExcessOfPlanAssetsDetails">
        <link:definition>101000 - Disclosure - Retirement Benefits - Accumulated Benefit Obligation In Excess of Plan Assets (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRetirementBenefitsNetPeriodicBenefitCostDetails" id="Role_DisclosureRetirementBenefitsNetPeriodicBenefitCostDetails">
        <link:definition>101010 - Disclosure - Retirement Benefits - Net Periodic Benefit Cost (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRetirementBenefitsAssumptionsUsedDetails" id="Role_DisclosureRetirementBenefitsAssumptionsUsedDetails">
        <link:definition>101020 - Disclosure - Retirement Benefits - Assumptions Used (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRetirementBenefitsAllocationOfPlanAssetsDetails" id="Role_DisclosureRetirementBenefitsAllocationOfPlanAssetsDetails">
        <link:definition>101030 - Disclosure - Retirement Benefits - Allocation of Plan Assets (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRetirementBenefitsFairValueDetails" id="Role_DisclosureRetirementBenefitsFairValueDetails">
        <link:definition>101040 - Disclosure - Retirement Benefits - Fair Value (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRetirementBenefitsFairValueReconciliationDetails" id="Role_DisclosureRetirementBenefitsFairValueReconciliationDetails">
        <link:definition>101050 - Disclosure - Retirement Benefits - Fair Value Reconciliation (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRetirementBenefitsSignificantUnobservableInputReconciliationDetails" id="Role_DisclosureRetirementBenefitsSignificantUnobservableInputReconciliationDetails">
        <link:definition>101060 - Disclosure - Retirement Benefits - Significant Unobservable Input Reconciliation (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRetirementBenefitsProjectedBenefitObligationDetails" id="Role_DisclosureRetirementBenefitsProjectedBenefitObligationDetails">
        <link:definition>101070 - Disclosure - Retirement Benefits - Projected Benefit Obligation (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureRetirementBenefitsExpectedBenefitPaymentsDetails" id="Role_DisclosureRetirementBenefitsExpectedBenefitPaymentsDetails">
        <link:definition>101080 - Disclosure - Retirement Benefits - Expected Benefit Payments (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureLeasesScheduleOfLeaseDetails" id="Role_DisclosureLeasesScheduleOfLeaseDetails">
        <link:definition>101090 - Disclosure - Leases - Schedule of Lease (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureLeasesScheduleOfAmountRecordedInConsolidatedStatementsOfComprehensiveIncomeDetails" id="Role_DisclosureLeasesScheduleOfAmountRecordedInConsolidatedStatementsOfComprehensiveIncomeDetails">
        <link:definition>101100 - Disclosure - Leases - Schedule of Amount Recorded in Consolidated Statements of Comprehensive Income (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureLeasesNarrativeDetails" id="Role_DisclosureLeasesNarrativeDetails">
        <link:definition>101110 - Disclosure - Leases - Narrative (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureLeasesScheduleOfCashPaidInMeasurementOfLeaseLiabilitiesDetails" id="Role_DisclosureLeasesScheduleOfCashPaidInMeasurementOfLeaseLiabilitiesDetails">
        <link:definition>101120 - Disclosure - Leases -Schedule of Cash Paid in the Measurement of Lease Liabilities (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureLeasesScheduleOfWeightedAverageTermAndDiscountRatesDetails" id="Role_DisclosureLeasesScheduleOfWeightedAverageTermAndDiscountRatesDetails">
        <link:definition>101130 - Disclosure - Leases - Schedule of Weighted Average Term and Discount Rates (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureLeasesScheduleOfMaturityOfOperatingAndFinanceLeasesLiabilitiesDetails" id="Role_DisclosureLeasesScheduleOfMaturityOfOperatingAndFinanceLeasesLiabilitiesDetails">
        <link:definition>101140 - Disclosure - Leases - Schedule of Maturity of Operating and Finance Leases Liabilities (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureLeasesScheduleOfMaturityOfOperatingAndFinanceLeasesLiabilitiesDetails2" id="Role_DisclosureLeasesScheduleOfMaturityOfOperatingAndFinanceLeasesLiabilitiesDetails2">
        <link:definition>101150 - Disclosure - Leases - Schedule of Maturity of Operating and Finance Leases Liabilities (Details)2</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureCommitmentsAndContingenciesNarrativeDetails" id="Role_DisclosureCommitmentsAndContingenciesNarrativeDetails">
        <link:definition>101160 - Disclosure - Commitments and Contingencies - Narrative (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureSupplementaryInformationForCertainBalanceSheetAccountsPrepaidAndOtherCurrentAssetsDetails" id="Role_DisclosureSupplementaryInformationForCertainBalanceSheetAccountsPrepaidAndOtherCurrentAssetsDetails">
        <link:definition>101170 - Disclosure - Supplementary Information for Certain Balance Sheet Accounts - Prepaid and Other Current Assets (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureSupplementaryInformationForCertainBalanceSheetAccountsOtherNonCurrentAssetsDetails" id="Role_DisclosureSupplementaryInformationForCertainBalanceSheetAccountsOtherNonCurrentAssetsDetails">
        <link:definition>101180 - Disclosure - Supplementary Information for Certain Balance Sheet Accounts - Other Non-current Assets (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureSupplementaryInformationForCertainBalanceSheetAccountsDeferredRevenueAndAccruedExpensesDetails" id="Role_DisclosureSupplementaryInformationForCertainBalanceSheetAccountsDeferredRevenueAndAccruedExpensesDetails">
        <link:definition>101190 - Disclosure - Supplementary Information for Certain Balance Sheet Accounts - Deferred Revenue and Accrued Expenses (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureSupplementaryInformationForCertainBalanceSheetAccountsOtherCurrentLiabilitiesDetails" id="Role_DisclosureSupplementaryInformationForCertainBalanceSheetAccountsOtherCurrentLiabilitiesDetails">
        <link:definition>101200 - Disclosure - Supplementary Information for Certain Balance Sheet Accounts - Other Current Liabilities (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureSupplementaryInformationForCertainBalanceSheetAccountsProvisionForLiabilitiesDetails" id="Role_DisclosureSupplementaryInformationForCertainBalanceSheetAccountsProvisionForLiabilitiesDetails">
        <link:definition>101210 - Disclosure - Supplementary Information for Certain Balance Sheet Accounts - Provision For Liabilities (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureSupplementaryInformationForCertainBalanceSheetAccountsOtherNonCurrentLiabilitiesDetails" id="Role_DisclosureSupplementaryInformationForCertainBalanceSheetAccountsOtherNonCurrentLiabilitiesDetails">
        <link:definition>101220 - Disclosure - Supplementary Information for Certain Balance Sheet Accounts - Other Non-current Liabilities (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureOtherIncomeNetDetails" id="Role_DisclosureOtherIncomeNetDetails">
        <link:definition>101230 - Disclosure - Other Income, Net (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureAccumulatedOtherComprehensiveLossComponentsOfOtherComprehensiveLossIncomeDetails" id="Role_DisclosureAccumulatedOtherComprehensiveLossComponentsOfOtherComprehensiveLossIncomeDetails">
        <link:definition>101240 - Disclosure - Accumulated Other Comprehensive Loss - Components of Other Comprehensive (Loss) Income (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureAccumulatedOtherComprehensiveLossScheduleOfAccumulatedOtherComprehensiveIncomeLossDetails" id="Role_DisclosureAccumulatedOtherComprehensiveLossScheduleOfAccumulatedOtherComprehensiveIncomeLossDetails">
        <link:definition>101250 - Disclosure - Accumulated Other Comprehensive Loss - Schedule of Accumulated Other Comprehensive Income (Loss) (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureAccumulatedOtherComprehensiveLossScheduleOfAccumulatedOtherComprehensiveIncomeLossParentheticalDetails" id="Role_DisclosureAccumulatedOtherComprehensiveLossScheduleOfAccumulatedOtherComprehensiveIncomeLossParentheticalDetails">
        <link:definition>101260 - Disclosure - Accumulated Other Comprehensive Loss - Schedule of Accumulated Other Comprehensive Income (Loss) (Parenthetical) (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureShareBasedCompensationNarrativeDetails" id="Role_DisclosureShareBasedCompensationNarrativeDetails">
        <link:definition>101270 - Disclosure - Share-Based Compensation - Narrative (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureShareBasedCompensationOptionsActivityDetails" id="Role_DisclosureShareBasedCompensationOptionsActivityDetails">
        <link:definition>101280 - Disclosure - Share-Based Compensation - Options Activity (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureShareBasedCompensationAssumptionsDetails" id="Role_DisclosureShareBasedCompensationAssumptionsDetails">
        <link:definition>101290 - Disclosure - Share-Based Compensation - Assumptions (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureShareBasedCompensationNonvestedRestrictedStockUnitsAndPerformanceBasedStockUnitsActivityDetails" id="Role_DisclosureShareBasedCompensationNonvestedRestrictedStockUnitsAndPerformanceBasedStockUnitsActivityDetails">
        <link:definition>101300 - Disclosure - Share-Based Compensation - Nonvested Restricted Stock Units and Performance Based Stock Units Activity (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureEarningsPerShareNarrativeDetails" id="Role_DisclosureEarningsPerShareNarrativeDetails">
        <link:definition>101310 - Disclosure - Earnings Per Share - Narrative (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureEarningsPerShareBasicAndDilutedEarningsPerShareDetails" id="Role_DisclosureEarningsPerShareBasicAndDilutedEarningsPerShareDetails">
        <link:definition>101320 - Disclosure - Earnings Per Share - Basic and Diluted Earnings Per Share (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.willistowerswatson.com/20201231/taxonomy/role/DisclosureSupplementalDisclosuresOfCashFlowInformationDetails" id="Role_DisclosureSupplementalDisclosuresOfCashFlowInformationDetails">
        <link:definition>101330 - Disclosure - Supplemental Disclosures of Cash Flow Information (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
    </xsd:appinfo>
  </xsd:annotation>
  <xsd:element id="wltw_EffectiveIncomeTaxRateReconciliationNonDeductibleAcquisitionCosts" name="EffectiveIncomeTaxRateReconciliationNonDeductibleAcquisitionCosts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_EffectiveIncomeTaxRateReconciliationEffectOfForeignExchangeAndOtherDifferences" name="EffectiveIncomeTaxRateReconciliationEffectOfForeignExchangeAndOtherDifferences" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_IncomeTaxReconciliationGlobalIntangibleLowTaxedIncome" name="IncomeTaxReconciliationGlobalIntangibleLowTaxedIncome" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_IncomeTaxReconciliationBaseErosionAntiAbuseTax" name="IncomeTaxReconciliationBaseErosionAntiAbuseTax" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_OtherForeignPlansMember" name="OtherForeignPlansMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_LeaseLiabilityPaymentsDueNextTwelveMonths" name="LeaseLiabilityPaymentsDueNextTwelveMonths" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_LeaseLiabilityPaymentsDueYearTwo" name="LeaseLiabilityPaymentsDueYearTwo" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_LeaseLiabilityPaymentsDueYearThree" name="LeaseLiabilityPaymentsDueYearThree" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_LeaseLiabilityPaymentsDueYearFour" name="LeaseLiabilityPaymentsDueYearFour" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_LeaseLiabilityPaymentsDueYearFive" name="LeaseLiabilityPaymentsDueYearFive" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_LeaseLiabilityPaymentsDueAfterYearFive" name="LeaseLiabilityPaymentsDueAfterYearFive" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_LeaseLiabilityUndiscountedExcessAmount" name="LeaseLiabilityUndiscountedExcessAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_LeaseLiability" name="LeaseLiability" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_DepreciationNotIncludingIntegrationComponent" name="DepreciationNotIncludingIntegrationComponent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_BusinessCombinationIntegrationRelatedCostsCredits" name="BusinessCombinationIntegrationRelatedCostsCredits" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_FiduciaryLiabilitiesCurrent" name="FiduciaryLiabilitiesCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_DeferredRevenueAndAccruedLiabilitiesCurrent" name="DeferredRevenueAndAccruedLiabilitiesCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_ProvisionForLiabilitiesNonCurrent" name="ProvisionForLiabilitiesNonCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_OrdinaryShareOneMember" name="OrdinaryShareOneMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_OrdinaryShareTwoMember" name="OrdinaryShareTwoMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_OperatingLeaseRightOfUseAssetAmortization" name="OperatingLeaseRightOfUseAssetAmortization" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_IncreaseDecreaseInFiduciaryAssets" name="IncreaseDecreaseInFiduciaryAssets" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_IncreaseDecreaseInFiduciaryLiabilities" name="IncreaseDecreaseInFiduciaryLiabilities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_IncreaseDecreaseInProvisionForLiabilities" name="IncreaseDecreaseInProvisionForLiabilities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_PaymentsToAcquireFixedAssetsAndSoftwareForInternalUse" name="PaymentsToAcquireFixedAssetsAndSoftwareForInternalUse" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_PaymentsForDeferredContingentConsiderationFinancingActivities" name="PaymentsForDeferredContingentConsiderationFinancingActivities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_TranzactCollateralizedFacilityMember" name="TranzactCollateralizedFacilityMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_DividendsAttributableToRedeemableNonControllingInterest" name="DividendsAttributableToRedeemableNonControllingInterest" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_OtherComprehensiveIncomeLossNetOfTaxIncludingPortionAttributableToNonredeemableNoncontrollingInterest" name="OtherComprehensiveIncomeLossNetOfTaxIncludingPortionAttributableToNonredeemableNoncontrollingInterest" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_OtherComprehensiveIncomeLossNetOfTaxAttributableToRedeemableNonControllingInterest" name="OtherComprehensiveIncomeLossNetOfTaxAttributableToRedeemableNonControllingInterest" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationAndNetSettlements" name="AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationAndNetSettlements" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_AdjustmentsToAdditionalPaidInCapitalForeignCurrencyTranslationGainLoss" name="AdjustmentsToAdditionalPaidInCapitalForeignCurrencyTranslationGainLoss" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_AcquisitionOfNoncontrollingInterestsRedeemable" name="AcquisitionOfNoncontrollingInterestsRedeemable" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_RedeemableNoncontrollingInterestMember" name="RedeemableNoncontrollingInterestMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_LesseeOperatingAndFinanceLeaseDisclosureTextBlock" name="LesseeOperatingAndFinanceLeaseDisclosureTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_RiskAndUncertaintiesPolicyTextBlock" name="RiskAndUncertaintiesPolicyTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_GoingConcernPolicyTextBlock" name="GoingConcernPolicyTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_FiduciaryAssetsAndFiduciaryLiabilitiesPolicyTextBlock" name="FiduciaryAssetsAndFiduciaryLiabilitiesPolicyTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_ScheduleOfFiniteLivedIntangibleAssetsAmortizationBasisAndExpectedLifeTableTextBlock" name="ScheduleOfFiniteLivedIntangibleAssetsAmortizationBasisAndExpectedLifeTableTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_ScheduleOfFinanceLeasedAssetsTableTextBlock" name="ScheduleOfFinanceLeasedAssetsTableTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_ScheduleOfNetPlanInvestmentsReconciliationToTotalFairValueOfPlanAssetsTableTextBlock" name="ScheduleOfNetPlanInvestmentsReconciliationToTotalFairValueOfPlanAssetsTableTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_ScheduleOfProjectedPensionContributionsTableTextBlock" name="ScheduleOfProjectedPensionContributionsTableTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_ScheduleOfLeaseTableTextBlock" name="ScheduleOfLeaseTableTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_ScheduleOfCashPaidForAmountInMeasurementOfLeaseLiabilitiesTableTextBlock" name="ScheduleOfCashPaidForAmountInMeasurementOfLeaseLiabilitiesTableTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_ScheduleOfWeightedAverageTermAndDiscountRatesForOperatingAndFinanceLeaseTableTextBlock" name="ScheduleOfWeightedAverageTermAndDiscountRatesForOperatingAndFinanceLeaseTableTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_LesseeOperatingAndFinanceLeaseLiabilityMaturityTableTextBlock" name="LesseeOperatingAndFinanceLeaseLiabilityMaturityTableTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_ProvisionsForLiabilitiesTableTextBlock" name="ProvisionsForLiabilitiesTableTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_ScheduleOfShareBasedPaymentAwardRestrictedStockUnitsValuationAssumptionsTableTextBlock" name="ScheduleOfShareBasedPaymentAwardRestrictedStockUnitsValuationAssumptionsTableTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_ProposedCombinationWithAONPlcMember" name="ProposedCombinationWithAONPlcMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_AonPlcMember" name="AonPlcMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_WillisTowersWatsonPublicLimitedCompanyMember" name="WillisTowersWatsonPublicLimitedCompanyMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_NumberOfSharesReceivableUponAcquisition" name="NumberOfSharesReceivableUponAcquisition" type="xbrli:pureItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="wltw_BusinessInterestDeductionsPercentage" name="BusinessInterestDeductionsPercentage" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_SignificantAccountingPoliciesAndRecentAccountingPronouncementsLineItems" name="SignificantAccountingPoliciesAndRecentAccountingPronouncementsLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_SignificantAccountingPoliciesAndRecentAccountingPronouncementsTable" name="SignificantAccountingPoliciesAndRecentAccountingPronouncementsTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_BaseErosionAntiAbuseTaxMember" name="BaseErosionAntiAbuseTaxMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_TaxYear2019And2020Member" name="TaxYear2019And2020Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_CARESMember" name="CARESMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_WillisLimitedMember" name="WillisLimitedMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_BrokingMember" name="BrokingMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_ConsultingMember" name="ConsultingMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_OutsourcedAdministrationMember" name="OutsourcedAdministrationMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_ReimbursedExpensesMember" name="ReimbursedExpensesMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_PercentageOfVotingRights" name="PercentageOfVotingRights" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_PercentageOfLeaseDenominatedInMajorCurrencies" name="PercentageOfLeaseDenominatedInMajorCurrencies" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="wltw_PortionOfRevenue" name="PortionOfRevenue" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_TermForRenewalCommissionsExpected" name="TermForRenewalCommissionsExpected" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_TRANZACTAcquisitionMember" name="TRANZACTAcquisitionMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_TermLoanMember" name="TermLoanMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_AlstonGaylerAcquisitionMember" name="AlstonGaylerAcquisitionMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_OtherAcquisitionsMember" name="OtherAcquisitionsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRestrictedCash" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRestrictedCash" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRenewalCommissionsReceivableCurrent" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRenewalCommissionsReceivableCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRenewalCommissionsReceivableNoncurrent" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRenewalCommissionsReceivableNoncurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseAssets" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseAssets" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCollateralizedFacility" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCollateralizedFacility" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_BusinessCombinationDeferredConsideration" name="BusinessCombinationDeferredConsideration" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_DisposalGroupIncludingDiscontinuedOperationNotesPayableInterestRate" name="DisposalGroupIncludingDiscontinuedOperationNotesPayableInterestRate" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_DispositionsAbstract" name="DispositionsAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_MaxMatthiessenMember" name="MaxMatthiessenMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_MillerMember" name="MillerMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_HumanCapitalAndBenefitsMember" name="HumanCapitalAndBenefitsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_CorporateRiskAndBrokingMember" name="CorporateRiskAndBrokingMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_InvestmentRiskAndReinsuranceMember" name="InvestmentRiskAndReinsuranceMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_BenefitsDeliveryAndAdministrationMember" name="BenefitsDeliveryAndAdministrationMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_IndividualRevenueStreamsPercentageOfTotalRevenue" name="IndividualRevenueStreamsPercentageOfTotalRevenue" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_BalanceSheetDateAxis" name="BalanceSheetDateAxis" type="xbrli:stringItemType" substitutionGroup="xbrldt:dimensionItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_BalanceSheetDateDomain" name="BalanceSheetDateDomain" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_December312019Member" name="December312019Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_GreatBritainMember" name="GreatBritainMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_WesternEuropeMember" name="WesternEuropeMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_InternationalMember" name="InternationalMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_ValuationAllowancesAndReservesForeignExchangeDifferences" name="ValuationAllowancesAndReservesForeignExchangeDifferences" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_CapitalizedContractCostAdditions" name="CapitalizedContractCostAdditions" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_CapitalizedContractCostForeignExchangeTranslationGainLoss" name="CapitalizedContractCostForeignExchangeTranslationGainLoss" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_BusinessCombinationIntegrationRelatedTransactionCosts" name="BusinessCombinationIntegrationRelatedTransactionCosts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_RestOfWorldMember" name="RestOfWorldMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_ForeignCountriesMember" name="ForeignCountriesMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_FederalAndForeignTaxAuthorityMember" name="FederalAndForeignTaxAuthorityMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_TaxYear2020Through2039Member" name="TaxYear2020Through2039Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_LegislationAxis" name="LegislationAxis" type="xbrli:stringItemType" substitutionGroup="xbrldt:dimensionItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_LegislationtypeDomain" name="LegislationtypeDomain" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_TaxCutsandJobsActMember" name="TaxCutsandJobsActMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_LegislationaspectAxis" name="LegislationaspectAxis" type="xbrli:stringItemType" substitutionGroup="xbrldt:dimensionItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_LegislationaspectDomain" name="LegislationaspectDomain" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_OneTimeTransitionTaxMember" name="OneTimeTransitionTaxMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_ExecutiveCompensationMember" name="ExecutiveCompensationMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_LegislationsectionAxis" name="LegislationsectionAxis" type="xbrli:stringItemType" substitutionGroup="xbrldt:dimensionItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_LegislationsectionDomain" name="LegislationsectionDomain" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_Section162mMember" name="Section162mMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_InternalRestructuringMember" name="InternalRestructuringMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_TaxYear2021Through2040Member" name="TaxYear2021Through2040Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_UKTaxMember" name="UKTaxMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_DomesticAndForeignTaxAuthorityMember" name="DomesticAndForeignTaxAuthorityMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_IncomeFromContinuingOperationsBeforeIncomeTaxesAndInterestInEarningsOfAssociatesLineItems" name="IncomeFromContinuingOperationsBeforeIncomeTaxesAndInterestInEarningsOfAssociatesLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_IncomeFromContinuingOperationsBeforeIncomeTaxesAndInterestInEarningsOfAssociatesTable" name="IncomeFromContinuingOperationsBeforeIncomeTaxesAndInterestInEarningsOfAssociatesTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_CurrentOtherJurisdictionsTaxExpenseBenefit" name="CurrentOtherJurisdictionsTaxExpenseBenefit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_DeferredOtherJurisdictionsTaxExpenseBenefit" name="DeferredOtherJurisdictionsTaxExpenseBenefit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_PercentOfMinimumTaxForTaxableIncomeAdjusted" name="PercentOfMinimumTaxForTaxableIncomeAdjusted" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_EffectiveIncomeTaxReconciliationForeignStatutoryIncomeTaxRate" name="EffectiveIncomeTaxReconciliationForeignStatutoryIncomeTaxRate" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_AccruedExpensesNotCurrentlyDeductible" name="AccruedExpensesNotCurrentlyDeductible" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_DeferredTaxAssetsOperatingLeaseLiabilities" name="DeferredTaxAssetsOperatingLeaseLiabilities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_DeferredTaxLiabilitiesOperatingLeaseRightOfUseAssets" name="DeferredTaxLiabilitiesOperatingLeaseRightOfUseAssets" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_DeferredTaxLiabilitiesMember" name="DeferredTaxLiabilitiesMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_ForeignEarningsThatCouldHaveBeenRepatriated" name="ForeignEarningsThatCouldHaveBeenRepatriated" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_AdditionalRepatriationAmountPreviouslyDeemedIndefinitelyReinvested" name="AdditionalRepatriationAmountPreviouslyDeemedIndefinitelyReinvested" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_UnrecognizedTaxBenefitsOtherIncreaseDecrease" name="UnrecognizedTaxBenefitsOtherIncreaseDecrease" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_OpenTaxYears" name="OpenTaxYears" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_PropertyPlantAndEquipmentAcquisitions" name="PropertyPlantAndEquipmentAcquisitions" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_ReclassificationOfPropertyPlantAndEquipment" name="ReclassificationOfPropertyPlantAndEquipment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_PropertyPlantAndEquipmentIncreaseDecreaseDueToForeignExchange" name="PropertyPlantAndEquipmentIncreaseDecreaseDueToForeignExchange" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_AbandonmentOfLongLivedAsset" name="AbandonmentOfLongLivedAsset" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_AccumulatedDepreciationDepletionAndAmortizationForeignExchange" name="AccumulatedDepreciationDepletionAndAmortizationForeignExchange" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_DepreciationExpenseExcludingAbandonmentOfInternallyDevelopedSoftwareAsset" name="DepreciationExpenseExcludingAbandonmentOfInternallyDevelopedSoftwareAsset" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_InternallyDevelopedSoftwareAssetMember" name="InternallyDevelopedSoftwareAssetMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_FinanceLeaseRightOfUseAssetGross" name="FinanceLeaseRightOfUseAssetGross" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_FinanceLeaseRightOfUseAssetAccumulatedDepreciation" name="FinanceLeaseRightOfUseAssetAccumulatedDepreciation" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_FiniteLivedIntangibleAssetsReclassificationOfFavorableLeaseAgreementAssetsToRightOfUseAssets" name="FiniteLivedIntangibleAssetsReclassificationOfFavorableLeaseAgreementAssetsToRightOfUseAssets" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_FiniteLivedIntangibleAssetsDisposed" name="FiniteLivedIntangibleAssetsDisposed" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_RevenueMember" name="RevenueMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_SalariesAndBenefitsMember" name="SalariesAndBenefitsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_DerivativeInstrumentsDesignatedAsHedgingInstrumentsGainLossNet" name="DerivativeInstrumentsDesignatedAsHedgingInstrumentsGainLossNet" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_TermLoanDueDecember2020Member" name="TermLoanDueDecember2020Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_CollateralizedFacilityMember" name="CollateralizedFacilityMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_Revolving125BillionDollarCreditFacilityMember" name="Revolving125BillionDollarCreditFacilityMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_SeniorNotesDue202105750Member" name="SeniorNotesDue202105750Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_SeniorNotesDue202103500Member" name="SeniorNotesDue202103500Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_SeniorNotesDue202202125Member" name="SeniorNotesDue202202125Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_SeniorNotesDue202304625Member" name="SeniorNotesDue202304625Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_SeniorNotesDue202403600Member" name="SeniorNotesDue202403600Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_SeniorNotesDue202604400Member" name="SeniorNotesDue202604400Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_SeniorNotesDue2028045Member" name="SeniorNotesDue2028045Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_SeniorNotesDue202902950Member" name="SeniorNotesDue202902950Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_SeniorNotesDue204306125Member" name="SeniorNotesDue204306125Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_SeniorNotesDue20480505Member" name="SeniorNotesDue20480505Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_SeniorNotesDue204903875Member" name="SeniorNotesDue204903875Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_DebtInstrumentMaturityYear" name="DebtInstrumentMaturityYear" type="xbrli:gYearItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_TermLoanFacilityMember" name="TermLoanFacilityMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_TermLoanDueDecember2019Member" name="TermLoanDueDecember2019Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_A3600seniornotesdue2024Member" name="A3600seniornotesdue2024Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_TrinityAcquisitionPlcMember" name="TrinityAcquisitionPlcMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_SeniorNotesDue2021and2026Member" name="SeniorNotesDue2021and2026Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_Revolving800MillionDollarCreditFacilityMember" name="Revolving800MillionDollarCreditFacilityMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_SeniorNotesDue2016Member" name="SeniorNotesDue2016Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_OneYearTermLoanFacilityDue2016TrancheTwoMember" name="OneYearTermLoanFacilityDue2016TrancheTwoMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_OneYearTermLoanFacilityDue2016Member" name="OneYearTermLoanFacilityDue2016Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_SeniorNotesDue20190700Member" name="SeniorNotesDue20190700Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_OneYearTermLoanMember" name="OneYearTermLoanMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_EURODenominatedMember" name="EURODenominatedMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_DebtInstrumentInterestAccrualDateDescription" name="DebtInstrumentInterestAccrualDateDescription" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_DebtInstrumentAdditionalBasisSpreadOnVariableRate1" name="DebtInstrumentAdditionalBasisSpreadOnVariableRate1" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_DebtInstrumentCommitmentFeePercentage" name="DebtInstrumentCommitmentFeePercentage" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="wltw_InterestOnSeniorNotesMember" name="InterestOnSeniorNotesMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_RevolvingOnePointTwoFiveBillionDollarCreditFacilityMember" name="RevolvingOnePointTwoFiveBillionDollarCreditFacilityMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_FairValueLevelOneLevelTwoOrLevelThreeTransfersAmount" name="FairValueLevelOneLevelTwoOrLevelThreeTransfersAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_DefinedBenefitPlansPercentageOfObligationFromPlans" name="DefinedBenefitPlansPercentageOfObligationFromPlans" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_CompensationAndRetirementDisclosureLineItems" name="CompensationAndRetirementDisclosureLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_CompensationAndRetirementDisclosureTable" name="CompensationAndRetirementDisclosureTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_EmployeeStatusAxis" name="EmployeeStatusAxis" type="xbrli:stringItemType" substitutionGroup="xbrldt:dimensionItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_EmployeeStatusDomain" name="EmployeeStatusDomain" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_NewlyEligibleEmployeesMember" name="NewlyEligibleEmployeesMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_DefinedContributionPlanTranchesAxis" name="DefinedContributionPlanTranchesAxis" type="xbrli:stringItemType" substitutionGroup="xbrldt:dimensionItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_DefinedContributionPlanTranchesDomain" name="DefinedContributionPlanTranchesDomain" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_DefinedContributionPlanTrancheOneMember" name="DefinedContributionPlanTrancheOneMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_DefinedContributionPlanTrancheTwoMember" name="DefinedContributionPlanTrancheTwoMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_DefinedBenefitPlanRequiredEmployeeContributionRate" name="DefinedBenefitPlanRequiredEmployeeContributionRate" type="xbrli:pureItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_DefinedBenefitPlanEmployeesCoveredPercentage" name="DefinedBenefitPlanEmployeesCoveredPercentage" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_MaximumAnnualSalaryAmount" name="MaximumAnnualSalaryAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_DefinedBenefitPlanFairValueOfPlanAssetsLiabilitiesReconciliation" name="DefinedBenefitPlanFairValueOfPlanAssetsLiabilitiesReconciliation" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_CostsRecognizedInNetPeriodicBenefitCostAndOtherComprehensiveIncome" name="CostsRecognizedInNetPeriodicBenefitCostAndOtherComprehensiveIncome" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_DefinedBenefitPlanAverageRemainingServicePeriod" name="DefinedBenefitPlanAverageRemainingServicePeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRateProjectedBenefitObligation" name="DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRateProjectedBenefitObligation" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRateServiceCost" name="DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRateServiceCost" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRateInterestCostOnServiceCost" name="DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRateInterestCostOnServiceCost" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRateInterestCostOnProjectedBenefitObligation" name="DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRateInterestCostOnProjectedBenefitObligation" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_WillisMember" name="WillisMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_WillisTowersWatsonMember" name="WillisTowersWatsonMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_TowersWatsonCoMember" name="TowersWatsonCoMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_CommingledFundsMember" name="CommingledFundsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_InsuranceContractsMember" name="InsuranceContractsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_DefinedBenefitPlanFairValueOfPlanAssetsLiabilities" name="DefinedBenefitPlanFairValueOfPlanAssetsLiabilities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_DefinedBenefitPlanFairValueOfPlanAssetsLiabilitiesNet" name="DefinedBenefitPlanFairValueOfPlanAssetsLiabilitiesNet" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_DefinedBenefitPlanNetAssetsHeldInInvestments" name="DefinedBenefitPlanNetAssetsHeldInInvestments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_DefinedBenefitPlanNetPayableReceivableForInvestmentsPurchased" name="DefinedBenefitPlanNetPayableReceivableForInvestmentsPurchased" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_DefinedBenefitPlanDividendAndInterestReceivable" name="DefinedBenefitPlanDividendAndInterestReceivable" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_DefinedBenefitPlanPurchases" name="DefinedBenefitPlanPurchases" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_DefinedBenefitPlanExpectedFutureBenefitPayments" name="DefinedBenefitPlanExpectedFutureBenefitPayments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_DefinedContributionPlanEmployersMatchingContributionEmployeeVestingPeriod" name="DefinedContributionPlanEmployersMatchingContributionEmployeeVestingPeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_LeaseRightOfUseAsset" name="LeaseRightOfUseAsset" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_LeaseLiabilityCurrent" name="LeaseLiabilityCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_LeaseLiabilityNoncurrent" name="LeaseLiabilityNoncurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_LeasePayment" name="LeasePayment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_LeaseLiabilityPaymentsDue" name="LeaseLiabilityPaymentsDue" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_LesseeLeaseLiabilitiesPaymentsDueAbstract" name="LesseeLeaseLiabilitiesPaymentsDueAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_TridentVParallelFundMember" name="TridentVParallelFundMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_DismissedLitigationMember" name="DismissedLitigationMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_SteinVWillisTowersWatsonPublicLimitedCompanyEtAlMember" name="SteinVWillisTowersWatsonPublicLimitedCompanyEtAlMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_KentVWillisTowersWatsonPublicLimitedCompanyEtAlMember" name="KentVWillisTowersWatsonPublicLimitedCompanyEtAlMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_CarterVWillisTowersWatsonPublicLimitedCompanyEtAlMember" name="CarterVWillisTowersWatsonPublicLimitedCompanyEtAlMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_TangVWillisTowersWatsonPublicLimitedCompanyEtAlMember" name="TangVWillisTowersWatsonPublicLimitedCompanyEtAlMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_KuznikVWillisTowersWatsonPublicLimitedCompanyEtAlMember" name="KuznikVWillisTowersWatsonPublicLimitedCompanyEtAlMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_LegacyTowersWatsonStockholdersMember" name="LegacyTowersWatsonStockholdersMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_LeadPlaintiffMember" name="LeadPlaintiffMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_WillisTowersWatsonMergerRelatedSecuritiesLitigationMember" name="WillisTowersWatsonMergerRelatedSecuritiesLitigationMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_LegacyTowersWatsonCityOfFortMyersGeneralEmployeesPensionFundFortMyersMember" name="LegacyTowersWatsonCityOfFortMyersGeneralEmployeesPensionFundFortMyersMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_AlaskaLaborersEmployersRetirementTrustAlaskaMember" name="AlaskaLaborersEmployersRetirementTrustAlaskaMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_RegentsMember" name="RegentsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_LegacyTowersWatsonNayaMasterFundLPNaya174FundLimitedAndNayaLincolnParkMasterFundLimitedCollectivelyNayaMember" name="LegacyTowersWatsonNayaMasterFundLPNaya174FundLimitedAndNayaLincolnParkMasterFundLimitedCollectivelyNayaMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_FederalActionMember" name="FederalActionMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_DelawareActionMember" name="DelawareActionMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_StanfordFinancialGroupMember" name="StanfordFinancialGroupMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_BusinessCombinationDeferredAndContingentConsideration" name="BusinessCombinationDeferredAndContingentConsideration" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_AmountPayableFromOption" name="AmountPayableFromOption" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_CapitalContributionObligation" name="CapitalContributionObligation" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_PrepaidExpenseAndAccruedRevenueReceivableCurrent" name="PrepaidExpenseAndAccruedRevenueReceivableCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_DerivativesAndInvestmentsCurrent" name="DerivativesAndInvestmentsCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_DeferredCompensationPlanAssetsCurrent" name="DeferredCompensationPlanAssetsCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_PrepaidBonusesCurrent" name="PrepaidBonusesCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_AcquiredRenewalCommissionReceivableCurrent" name="AcquiredRenewalCommissionReceivableCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_PrepaidExpenseAndAccruedRevenueReceivableNoncurrent" name="PrepaidExpenseAndAccruedRevenueReceivableNoncurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_AcquiredRenewalCommissionsReceivableNonCurrent" name="AcquiredRenewalCommissionsReceivableNonCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_AccruedDiscretionaryAndIncentiveCompensation" name="AccruedDiscretionaryAndIncentiveCompensation" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_BusinessCombinationContingentConsiderationLiabilityAndDeferredConsiderationCurrent" name="BusinessCombinationContingentConsiderationLiabilityAndDeferredConsiderationCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_PayrollRelatedLiabilitiesCurrent" name="PayrollRelatedLiabilitiesCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_BusinessCombinationContingentConsiderationLiabilityAndDeferredConsiderationNoncurrent" name="BusinessCombinationContingentConsiderationLiabilityAndDeferredConsiderationNoncurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_UnrecognizedTaxBenefitsIncludingInterest" name="UnrecognizedTaxBenefitsIncludingInterest" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_MiscellaneousOtherNonOperatingIncomeExpense" name="MiscellaneousOtherNonOperatingIncomeExpense" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_A2012EquityIncentivePlanMember" name="A2012EquityIncentivePlanMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_RestrictedStockUnitsRSUAndOptionsMember" name="RestrictedStockUnitsRSUAndOptionsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_TowersWatsonCo2009LongTermIncentivePlanMember" name="TowersWatsonCo2009LongTermIncentivePlanMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_PreAcquisitionMember" name="PreAcquisitionMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_PostAcquisitionMember" name="PostAcquisitionMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_TimeBasedStockOptionsMember" name="TimeBasedStockOptionsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_PerformanceBasedStockOptionsMember" name="PerformanceBasedStockOptionsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_PhantomRestrictedStockUnitsMember" name="PhantomRestrictedStockUnitsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueOutstandingOne" name="SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueOutstandingOne" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="wltw_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsCancelledInPeriod" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsCancelledInPeriod" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsVestedinPeriodWeightedAverageGrantDateSharePrice" name="SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsVestedinPeriodWeightedAverageGrantDateSharePrice" type="num:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_EmployeeServicesShareBasedCompensationTaxBenefitRealizedFromVestingOfRSUs" name="EmployeeServicesShareBasedCompensationTaxBenefitRealizedFromVestingOfRSUs" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="wltw_TimeBasedSharesMember" name="TimeBasedSharesMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="wltw_DilutiveSecuritiesEffectOnBasicEarningsPerShare" name="DilutiveSecuritiesEffectOnBasicEarningsPerShare" type="num:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="wltw_NonCashOrPartNonCashAcquisitionFairValueOfDeferredAndContingentConsideration" name="NonCashOrPartNonCashAcquisitionFairValueOfDeferredAndContingentConsideration" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
</xsd:schema>
