<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2015-09-18</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001467760</issuerCik>
        <issuerName>Apollo Commercial Real Estate Finance, Inc.</issuerName>
        <issuerTradingSymbol>ARI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001441449</rptOwnerCik>
            <rptOwnerName>Qatar Investment Authority</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>P.O. BOX 23224 Q-TEL TOWER, 8TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2>DIPLOMATIC AREA STREET, WEST BAY</rptOwnerStreet2>
            <rptOwnerCity>DOHA</rptOwnerCity>
            <rptOwnerState>S3</rptOwnerState>
            <rptOwnerZipCode>QATAR</rptOwnerZipCode>
            <rptOwnerStateDescription>QATAR</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001654220</rptOwnerCik>
            <rptOwnerName>QH RE Asset Co LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>Q-TEL TOWER, DIPLOMATIC AREA STREET</rptOwnerStreet1>
            <rptOwnerStreet2>WEST BAY, P.O. BOX: 23224</rptOwnerStreet2>
            <rptOwnerCity>DOHA</rptOwnerCity>
            <rptOwnerState>S3</rptOwnerState>
            <rptOwnerZipCode>QATAR</rptOwnerZipCode>
            <rptOwnerStateDescription>QATAR</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>8823529</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The Common Stock is directly held by QH RE Asset Company LLC, a wholly-owned subsidiary of Qatar Investment Authority. The Reporting Persons disclaim beneficial ownership of the securities reported herein except to the extent of their pecuniary interest therein and this report shall not be deemed an admission that any such Reporting Person is the beneficial owner of, or has any pecuniary interest in, such securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Ahmad Al-Khanji</signatureName>
        <signatureDate>2015-09-28</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Ian R. Kellow, Head of Compliance, Qatar Investment Authority</signatureName>
        <signatureDate>2015-09-28</signatureDate>
    </ownerSignature>
</ownershipDocument>
