<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019e65d5-3f3e-706f-93be-3185b0837ae0,g:1c1bb978-33d3-459b-8a36-cf95a6f59de9-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://www.zillowgroup.com/role/Cover" xlink:type="simple" xlink:href="z-20260602.xsd#Cover"/>
  <link:definitionLink xlink:role="http://www.zillowgroup.com/role/Cover" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitiesTable_019e65d5-3f3e-786c-83a2-e54dcf27336c" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntitiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:to="loc_dei_EntitiesTable_019e65d5-3f3e-786c-83a2-e54dcf27336c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019e65d5-3f3e-7d03-a7cd-ada38ad10368" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_EntitiesTable_019e65d5-3f3e-786c-83a2-e54dcf27336c" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019e65d5-3f3e-7d03-a7cd-ada38ad10368" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019e65d5-3f3e-7d03-a7cd-ada38ad10368_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019e65d5-3f3e-7d03-a7cd-ada38ad10368" xlink:to="loc_us-gaap_ClassOfStockDomain_019e65d5-3f3e-7d03-a7cd-ada38ad10368_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019e65d5-3f3e-793d-ad9a-f28494bf6576" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019e65d5-3f3e-7d03-a7cd-ada38ad10368" xlink:to="loc_us-gaap_ClassOfStockDomain_019e65d5-3f3e-793d-ad9a-f28494bf6576" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019e65d5-3f3e-7751-b8a4-3999cd1c6316" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019e65d5-3f3e-793d-ad9a-f28494bf6576" xlink:to="loc_us-gaap_CommonClassAMember_019e65d5-3f3e-7751-b8a4-3999cd1c6316" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassCMember_019e65d5-3f3e-70e5-ae7c-d36c323987ef" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019e65d5-3f3e-793d-ad9a-f28494bf6576" xlink:to="loc_us-gaap_CommonClassCMember_019e65d5-3f3e-70e5-ae7c-d36c323987ef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_019e65d5-3f3e-7d64-9d22-6e19ccb65e79" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentType"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:to="loc_dei_DocumentType_019e65d5-3f3e-7d64-9d22-6e19ccb65e79" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_019e65d5-3f3e-7dd9-9970-9352276769e7" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentPeriodEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:to="loc_dei_DocumentPeriodEndDate_019e65d5-3f3e-7dd9-9970-9352276769e7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_019e65d5-3f3e-7dcf-9881-73e75c57f361" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityRegistrantName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:to="loc_dei_EntityRegistrantName_019e65d5-3f3e-7dcf-9881-73e75c57f361" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_019e65d5-3f3e-7117-af26-25bd4f0df7a3" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_AmendmentFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:to="loc_dei_AmendmentFlag_019e65d5-3f3e-7117-af26-25bd4f0df7a3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_019e65d5-3f3e-7ad4-b1a9-7c95db977124" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCentralIndexKey"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:to="loc_dei_EntityCentralIndexKey_019e65d5-3f3e-7ad4-b1a9-7c95db977124" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_019e65d5-3f3e-7159-893f-c8c207264c1e" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:to="loc_dei_EntityIncorporationStateCountryCode_019e65d5-3f3e-7159-893f-c8c207264c1e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_019e65d5-3f3e-7785-940b-a02e33d6e756" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityFileNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:to="loc_dei_EntityFileNumber_019e65d5-3f3e-7785-940b-a02e33d6e756" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_019e65d5-3f3e-7611-b468-8aa8dfc8a24f" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:to="loc_dei_EntityTaxIdentificationNumber_019e65d5-3f3e-7611-b468-8aa8dfc8a24f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_019e65d5-3f3e-7177-aeea-9ee90cd6c562" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressAddressLine1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:to="loc_dei_EntityAddressAddressLine1_019e65d5-3f3e-7177-aeea-9ee90cd6c562" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine2_019e65d5-3f3e-7c0b-a9b8-25d812375833" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressAddressLine2"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:to="loc_dei_EntityAddressAddressLine2_019e65d5-3f3e-7c0b-a9b8-25d812375833" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_019e65d5-3f3e-7800-85f0-9a5b482d3e5e" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressCityOrTown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:to="loc_dei_EntityAddressCityOrTown_019e65d5-3f3e-7800-85f0-9a5b482d3e5e" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_019e65d5-3f3f-726c-8cda-f84da802a08d" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressStateOrProvince"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:to="loc_dei_EntityAddressStateOrProvince_019e65d5-3f3f-726c-8cda-f84da802a08d" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_019e65d5-3f3f-7785-a19f-0b09e36e491e" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressPostalZipCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:to="loc_dei_EntityAddressPostalZipCode_019e65d5-3f3f-7785-a19f-0b09e36e491e" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_019e65d5-3f3f-7f03-a6c1-3ada796b377f" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_CityAreaCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:to="loc_dei_CityAreaCode_019e65d5-3f3f-7f03-a6c1-3ada796b377f" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_019e65d5-3f3f-7d8f-a33b-32b21e38452b" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LocalPhoneNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:to="loc_dei_LocalPhoneNumber_019e65d5-3f3f-7d8f-a33b-32b21e38452b" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_WrittenCommunications_019e65d5-3f3f-7a93-9049-f0b916d84880" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_WrittenCommunications"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:to="loc_dei_WrittenCommunications_019e65d5-3f3f-7a93-9049-f0b916d84880" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SolicitingMaterial_019e65d5-3f3f-7c26-92ac-e6d990a8bc9e" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_SolicitingMaterial"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:to="loc_dei_SolicitingMaterial_019e65d5-3f3f-7c26-92ac-e6d990a8bc9e" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_PreCommencementTenderOffer_019e65d5-3f3f-776a-913b-933be1b954fa" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_PreCommencementTenderOffer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:to="loc_dei_PreCommencementTenderOffer_019e65d5-3f3f-776a-913b-933be1b954fa" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_PreCommencementIssuerTenderOffer_019e65d5-3f3f-7836-9e47-2055cbd6f670" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_PreCommencementIssuerTenderOffer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:to="loc_dei_PreCommencementIssuerTenderOffer_019e65d5-3f3f-7836-9e47-2055cbd6f670" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_019e65d5-3f3f-703b-b9f9-d7982d8b96dd" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_Security12bTitle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:to="loc_dei_Security12bTitle_019e65d5-3f3f-703b-b9f9-d7982d8b96dd" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_019e65d5-3f3f-70d7-9f4c-932b51b6cea3" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_TradingSymbol"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:to="loc_dei_TradingSymbol_019e65d5-3f3f-70d7-9f4c-932b51b6cea3" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_019e65d5-3f3f-74a6-8190-bd2ee3408968" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_SecurityExchangeName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:to="loc_dei_SecurityExchangeName_019e65d5-3f3f-74a6-8190-bd2ee3408968" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_019e65d5-3f3f-71d5-b361-feef75419fef" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e65d5-3f3e-72b1-bdcb-bd0814c7a374" xlink:to="loc_dei_EntityEmergingGrowthCompany_019e65d5-3f3f-71d5-b361-feef75419fef" xlink:type="arc" order="22"/>
  </link:definitionLink>
</link:linkbase>
