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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-04-02</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001546381</issuerCik>
        <issuerName>RLJ ENTERTAINMENT, INC.</issuerName>
        <issuerTradingSymbol>RLJE</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001514991</rptOwnerCik>
            <rptOwnerName>AMC Networks Inc.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>11 PENN PLAZA</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10001</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2018-04-02</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>409162</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4230750</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Subsidiary</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2018-04-02</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>38161</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>4.47</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4268911</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Subsidiary</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">RLJ Entertainment, Inc. (&quot;RLJE&quot;) issued 409,162 shares of common stock, par value $0.001 per share (&quot;Common Stock&quot;), of RLJE reported herein to Digital Entertainment Holdings LLC (&quot;DEH&quot;), an indirect wholly-owned subsidiary of AMC Networks Inc. (&quot;AMC&quot;), as payment of interest due to DEH pursuant to that certain Credit and Guaranty Agreement, by and among RLJE, certain subsidiaries of RLJE as Guarantors, and DEH, dated as of October 14, 2016, as amended by the First Amendment dated as of January 30, 2017 and the Second Amendment dated as of June 16, 2017.</footnote>
        <footnote id="F2">Pursuant to a Stock Purchase Agreement by and between DEH and RLJE, dated as of April 2, 2018, DEH purchased 38,161 shares of Common Stock from RLJE on behalf of certain employees of RLJE for an aggregate purchase price of $170,579.67.</footnote>
        <footnote id="F3">AMC may be deemed to beneficially own the shares of Common Stock indirectly through its wholly-owned subsidiaries.  The Common Stock is held directly by DEH, a direct wholly-owned subsidiary of IFC Entertainment Holdings LLC.  IFC Entertainment Holdings LLC is a direct wholly-owned subsidiary of Rainbow Programming Holdings LLC.  Rainbow Programming Holdings LLC is a direct wholly-owned subsidiary of Rainbow Media Enterprises, Inc.  Rainbow Media Enterprises, Inc. is a direct wholly-owned subsidiary of Rainbow Media Holdings, LLC.  Rainbow Media Holdings, LLC is a direct wholly-owned subsidiary of AMC.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Anne G. Kelly, Senior Vice President and Secretary of AMC Networks Inc.</signatureName>
        <signatureDate>2018-04-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
