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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-07-19</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001630472</issuerCik>
        <issuerName>TPG RE Finance Trust, Inc.</issuerName>
        <issuerTradingSymbol>TRTX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001298783</rptOwnerCik>
            <rptOwnerName>Foley Robert</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O TPG RE FINANCE TRUST, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>888 SEVENTH AVENUE, 35TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10106</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Financial Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-07-19</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5797</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>13.55</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>81430</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3215</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Explanation of Responses</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">On July 19, 2021, TPG RE Finance Trust, Inc. (the &quot;Issuer&quot;) withheld 5,797 shares of common stock (&quot;Common Stock&quot;) of the Issuer from Mr. Foley for payment of the tax liability incident to the vesting of shares of Common Stock granted by the Issuer pursuant to the terms of the Issuer's 2017 Equity Incentive Plan.</footnote>
        <footnote id="F2">Represents shares of Common Stock of the Issuer that have been awarded by TPG RE Finance Trust Management, L.P. (the &quot;Manager&quot;), the external manager of the Issuer, to Mr. Foley in accordance with the terms of a compensatory plan adopted by the Manager.  Upon vesting, the shares of Common Stock will be delivered to Mr. Foley.</footnote>
    </footnotes>

    <remarks>(3)  Matthew Coleman is signing on behalf of Mr. Foley pursuant to the power of attorney dated July 5, 2017, which was previously filed with the Securities and Exchange Commission.</remarks>

    <ownerSignature>
        <signatureName>/s/ Matthew Coleman, By: Matthew Coleman, on behalf of Robert Foley (3)</signatureName>
        <signatureDate>2021-07-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
