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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2016-11-29</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001459417</issuerCik>
        <issuerName>2U, Inc.</issuerName>
        <issuerTradingSymbol>TWOU</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001241953</rptOwnerCik>
            <rptOwnerName>STAVIS ROBERT M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O 2U, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>8201 CORPORATE DRIVE, SUITE 900</rptOwnerStreet2>
            <rptOwnerCity>LANDOVER</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>20785</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>2016-11-29</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>
                    <value>0.00</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>111908</value>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">On November 29, 2016, Bessemer Venture Partners VII, L.P. (&quot;BVP VII&quot;) sold 2,318 shares of Common Stock of the Issuer (the &quot;shares&quot;), Bessemer Venture Partners VII Institutional L.P. (&quot;BVP VII Inst&quot;) sold 1,013 shares, and BVP VII Special Opportunity Fund L.P. (&quot;BVP VII SOF,&quot; and together with BVP VII and BVP VII Inst, the &quot;Funds&quot;) sold 3,907 shares.  The shares were sold in one execution at a price per share of $35.24.</footnote>
        <footnote id="F2">After the reported transaction, none of the Funds owned any shares.</footnote>
        <footnote id="F3">The reporting person is a director of Deer VII &amp; Co. Ltd, which is the general partner of Deer VII &amp; Co. L.P., 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 the securities by virtue of his interest in Deer VII &amp; Co. Ltd., his interest in Deer VII &amp; Co. L.P. 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>
        <footnote id="F4">The amount reported includes 12,331 restricted stock units, each of which represents a contingent right to receive one share of common stock of the issuer. The restricted stock units are held directly by the reporting person. 28,130 shares are held directly by the reporting person, 35,707 shares are held by Stavis Ventures II, LLC (&quot;Stavis Ventures&quot;), and the remaining 35,740 shares are held by Stavco Venture Holdings LLC (&quot;Stavco Venture Holdings&quot;). Stavis Ventures and Stavco Venture Holdings are controlled by the reporting person, and the reporting person disclaims beneficial ownership of the shares held by these entities, except to the extent of his pecuniary interest therein, if any.</footnote>
        <footnote id="F5">Includes 19,585 shares, 24,860 shares and 24,218 shares received by the reporting person, Stavis Ventures and Stavco Venture Holdings, respectively, in distributions-in-kind by the Funds on November 22, 2016, which distributions were made in accordance with the exemptions afforded by Rules 16a-9 and 16a-13 of the Securities Exchange Act of 1934, as amended.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Robert Stavis</signatureName>
        <signatureDate>2016-12-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
