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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-11-16</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001625641</issuerCik>
        <issuerName>CS Disco, Inc.</issuerName>
        <issuerTradingSymbol>LAW</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001252022</rptOwnerCik>
            <rptOwnerName>GOODMAN ROBERT P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O CS DISCO, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>3700 N. CAPITAL OF TEXAS HWY., SUITE 150</rptOwnerStreet2>
            <rptOwnerCity>AUSTIN</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>78746</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-11-16</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>0</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">On November 16, 2021 Bessemer Venture Partners VIII Institutional L.P. (&quot;BVP VIII Inst&quot;) and Bessemer Venture Partners VIII, L.P. (&quot;BVP VIII&quot;, together with BVP VIII Inst referred to collectively, the &quot;Funds&quot;) sold 655,200 shares and 544,800 shares of Common Stock of CS Disco, Inc., respectively, in a single execution of $51.00 per share</footnote>
        <footnote id="F2">Following the reported transactions, BVP VIII Inst and BVP VIII own 5,435,631 shares of Common Stock and 4,519,741 shares of Common Stock, respectively.</footnote>
        <footnote id="F3">The Reporting Person is a director of Deer VIII &amp; Co. Ltd (&quot;Deer VIII Ltd.&quot;), which is the general partner of Deer VIII &amp; Co. L.P. (&quot;Deer VIII LP&quot;), which is the general partner of each of the Funds. The Reporting Person disclaims beneficial ownership of the securities held by the Funds, except to the extent of his pecuniary interest, if any, in such securities by virtue of his interest in Deer VIII Ltd. and Deer VIII LP and his indirect limited partnership interest in the Funds. This report shall not be deemed an admission that the Reporting Person is the beneficial owner of such securities.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Robert P. Goodman</signatureName>
        <signatureDate>2021-11-18</signatureDate>
    </ownerSignature>
</ownershipDocument>
