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

    <schemaVersion>X0508</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2021-08-11</periodOfReport>

    <dateOfOriginalSubmission>2021-08-13</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001753162</issuerCik>
        <issuerName>Fathom Holdings Inc.</issuerName>
        <issuerTradingSymbol>FTHM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001817237</rptOwnerCik>
            <rptOwnerName>Harley Joshua</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O FATHOM HOLDINGS INC.</rptOwnerStreet1>
            <rptOwnerStreet2>2000 REGENCY PARKWAY DRIVE, SUITE 300</rptOwnerStreet2>
            <rptOwnerCity>CARY</rptOwnerCity>
            <rptOwnerState>NC</rptOwnerState>
            <rptOwnerZipCode>27518</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Executive Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>1</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-08-12</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2020</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>34.03</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3198040</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F3"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3196565</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F3"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 Sales Plan adopted by the reporting person on May 17, 2021.</footnote>
        <footnote id="F2">The reported securities were sold in multiple transactions at prices ranging from $34.00 to $34.23. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within such range.</footnote>
        <footnote id="F3">Of these shares, 9,558 shares are restricted and vest in full on March 4, 2024.</footnote>
    </footnotes>

    <remarks>This amendment is filed to correct the amount of shares sold on 08/12/2021 from the originally reported 13,516 shares to the correct amount of 2,020 shares.  The total shares reflected as owned directly in the line after the line in which the amended transaction is reported incorporates all transactions reported on the original Form 4.  All other information in the original Form 4 remains unchanged.</remarks>

    <ownerSignature>
        <signatureName>/s/ Donald R. Reynolds, by Power of Attorney</signatureName>
        <signatureDate>2023-08-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
