<?xml version="1.0" encoding="us-ascii"?>
<!-- DFIN ActiveDisclosure(SM) XBRL Linkbase Document - http://www.dfinsolutions.com/ -->
<!-- Creation Date      : 2021-02-04T16:03:35.8546266+00:00 -->
<!-- Version            : 5.0.1.571 -->
<!-- Package ID         : b4faec3f42ac4a818dc3b25ab3bc8c2c -->
<!-- Copyright (c) 2021 Donnelley Financial Solutions, Inc. All Rights Reserved. -->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" arcroleURI="http://xbrl.org/int/dim/arcrole/all" />
  <link:arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" />
  <link:arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" />
  <link:arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" />
  <link:arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" />
  <link:roleRef xlink:type="simple" xlink:href="hst-20210203.xsd#TemplateLink" roleURI="http://www.hosthotels.com/20210203/role/TemplateLink" />
  <link:roleRef roleURI="http://www.hosthotels.com/20210203/taxonomy/role/DocumentCoverPage" xlink:href="hst-20210203.xsd#Role_DocumentCoverPage" xlink:type="simple" />
  <link:definitionLink xlink:type="extended" xlink:role="http://www.hosthotels.com/20210203/taxonomy/role/DocumentCoverPage">
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_SecurityExchangeName" xlink:type="locator" xlink:label="dei_SecurityExchangeName" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_TradingSymbol" xlink:type="locator" xlink:label="dei_TradingSymbol" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_Security12bTitle" xlink:type="locator" xlink:label="dei_Security12bTitle" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_PreCommencementIssuerTenderOffer" xlink:type="locator" xlink:label="dei_PreCommencementIssuerTenderOffer" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_PreCommencementTenderOffer" xlink:type="locator" xlink:label="dei_PreCommencementTenderOffer" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_SolicitingMaterial" xlink:type="locator" xlink:label="dei_SolicitingMaterial" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_WrittenCommunications" xlink:type="locator" xlink:label="dei_WrittenCommunications" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LocalPhoneNumber" xlink:type="locator" xlink:label="dei_LocalPhoneNumber" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_CityAreaCode" xlink:type="locator" xlink:label="dei_CityAreaCode" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityAddressPostalZipCode" xlink:type="locator" xlink:label="dei_EntityAddressPostalZipCode" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityAddressStateOrProvince" xlink:type="locator" xlink:label="dei_EntityAddressStateOrProvince" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityAddressCityOrTown" xlink:type="locator" xlink:label="dei_EntityAddressCityOrTown" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityAddressAddressLine2" xlink:type="locator" xlink:label="dei_EntityAddressAddressLine2" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityAddressAddressLine1" xlink:type="locator" xlink:label="dei_EntityAddressAddressLine1" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityTaxIdentificationNumber" xlink:type="locator" xlink:label="dei_EntityTaxIdentificationNumber" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityIncorporationStateCountryCode" xlink:type="locator" xlink:label="dei_EntityIncorporationStateCountryCode" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityFileNumber" xlink:type="locator" xlink:label="dei_EntityFileNumber" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityEmergingGrowthCompany" xlink:type="locator" xlink:label="dei_EntityEmergingGrowthCompany" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityCentralIndexKey" xlink:type="locator" xlink:label="dei_EntityCentralIndexKey" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityRegistrantName" xlink:type="locator" xlink:label="dei_EntityRegistrantName" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_DocumentPeriodEndDate" xlink:type="locator" xlink:label="dei_DocumentPeriodEndDate" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_AmendmentFlag" xlink:type="locator" xlink:label="dei_AmendmentFlag" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_DocumentType" xlink:type="locator" xlink:label="dei_DocumentType" />
    <link:loc xlink:href="hst-20210203.xsd#hst_HostHotelsAndResortsLimitedPartnershipSubsidiariesMember" xlink:type="locator" xlink:label="hst_HostHotelsAndResortsLimitedPartnershipSubsidiariesMember" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain_2" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <link:loc xlink:href="hst-20210203.xsd#hst_DocumentAndEntityInformationTable" xlink:type="locator" xlink:label="hst_DocumentAndEntityInformationTable" />
    <link:loc xlink:href="hst-20210203.xsd#hst_DocumentAndEntityInformationLineItems" xlink:type="locator" xlink:label="hst_DocumentAndEntityInformationLineItems" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="hst_DocumentAndEntityInformationLineItems" xlink:to="hst_DocumentAndEntityInformationTable" order="10010.00" priority="2" use="optional" xbrldt:contextElement="segment" xbrldt:closed="true" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="hst_DocumentAndEntityInformationTable" xlink:to="dei_LegalEntityAxis" order="10040.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain_2" order="10050.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10070.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_EntityDomain" xlink:to="hst_HostHotelsAndResortsLimitedPartnershipSubsidiariesMember" order="10090.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="hst_DocumentAndEntityInformationLineItems" xlink:to="dei_DocumentType" order="10120.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="hst_DocumentAndEntityInformationLineItems" xlink:to="dei_AmendmentFlag" order="10160.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="hst_DocumentAndEntityInformationLineItems" xlink:to="dei_DocumentPeriodEndDate" order="10200.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="hst_DocumentAndEntityInformationLineItems" xlink:to="dei_EntityRegistrantName" order="10240.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="hst_DocumentAndEntityInformationLineItems" xlink:to="dei_EntityCentralIndexKey" order="10280.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="hst_DocumentAndEntityInformationLineItems" xlink:to="dei_EntityEmergingGrowthCompany" order="10320.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="hst_DocumentAndEntityInformationLineItems" xlink:to="dei_EntityFileNumber" order="10360.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="hst_DocumentAndEntityInformationLineItems" xlink:to="dei_EntityIncorporationStateCountryCode" order="10400.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="hst_DocumentAndEntityInformationLineItems" xlink:to="dei_EntityTaxIdentificationNumber" order="10440.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="hst_DocumentAndEntityInformationLineItems" xlink:to="dei_EntityAddressAddressLine1" order="10480.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="hst_DocumentAndEntityInformationLineItems" xlink:to="dei_EntityAddressAddressLine2" order="10520.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="hst_DocumentAndEntityInformationLineItems" xlink:to="dei_EntityAddressCityOrTown" order="10560.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="hst_DocumentAndEntityInformationLineItems" xlink:to="dei_EntityAddressStateOrProvince" order="10600.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="hst_DocumentAndEntityInformationLineItems" xlink:to="dei_EntityAddressPostalZipCode" order="10640.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="hst_DocumentAndEntityInformationLineItems" xlink:to="dei_CityAreaCode" order="10680.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="hst_DocumentAndEntityInformationLineItems" xlink:to="dei_LocalPhoneNumber" order="10720.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="hst_DocumentAndEntityInformationLineItems" xlink:to="dei_WrittenCommunications" order="10760.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="hst_DocumentAndEntityInformationLineItems" xlink:to="dei_SolicitingMaterial" order="10800.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="hst_DocumentAndEntityInformationLineItems" xlink:to="dei_PreCommencementTenderOffer" order="10840.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="hst_DocumentAndEntityInformationLineItems" xlink:to="dei_PreCommencementIssuerTenderOffer" order="10880.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="hst_DocumentAndEntityInformationLineItems" xlink:to="dei_Security12bTitle" order="10950.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="hst_DocumentAndEntityInformationLineItems" xlink:to="dei_TradingSymbol" order="11010.00" priority="2" use="optional" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="hst_DocumentAndEntityInformationLineItems" xlink:to="dei_SecurityExchangeName" order="11070.00" priority="2" use="optional" />
  </link:definitionLink>
</link:linkbase>
