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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-05-12</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001082506</issuerCik>
        <issuerName>Great Elm Capital Group, Inc.</issuerName>
        <issuerTradingSymbol>GEC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001458693</rptOwnerCik>
            <rptOwnerName>Drapkin Matthew A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O NORTHERN RIGHT CAPITAL MANAGEMENT</rptOwnerStreet1>
            <rptOwnerStreet2>10 CORBIN DRIVE, 3RD FLOOR</rptOwnerStreet2>
            <rptOwnerCity>DARIEN</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06820</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>2017-05-12</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1136792</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.35</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1136792</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares of Common Stock, $0.001 Par Value (the &quot;Common Stock&quot;), of Great Elm Capital Group, Inc., a Delaware corporation (f/k/a Unwired Planet, Inc.) (the &quot;Issuer&quot;) directly held by Northern Right Capital (QP), L.P. (&quot;Northern Right&quot;).</footnote>
        <footnote id="F2">Mr. Drapkin may be deemed to beneficially own such Common Stock as he is a member of BC Advisors, LLC, which is the general partner of Northern Right Capital Management, L.P., and Northern Right Capital Management, L.P. is the general partner of, and investment manager for, Northern Right.  Mr. Drapkin disclaims beneficial ownership in such Common Stock except to the extent of his pecuniary interest therein</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Matthew A. Drapkin</signatureName>
        <signatureDate>2017-05-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
