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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-10-04</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>L.P., 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>2017-10-04</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1266000</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.6116</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2402792</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares of common stock of Great Elm Capital Group, Inc. (the &quot;Issuer&quot;), par value $0.001 per share (the &quot;Common Stock&quot;), purchased by Northern Right Capital Management, L.P., a Texas limited partnership (&quot;Northern Right Management&quot;), on behalf of a separate managed account on behalf of an investment advisory client (the &quot;Managed Account&quot;) pursuant to the exercise of a warrant (the &quot;Warrant&quot;) issued by the Issuer to Northern Right Management on September 18, 2017.</footnote>
        <footnote id="F2">The price reported in Column 4 represents the exercise price for the Warrant, which is the simple average of the Weighted Average Price (as defined in the Warrant) of the Common Stock on the principal securities market on which the Common Stock is then traded for the ten (10) consecutive trading days ending on and including October 4, 2017.</footnote>
        <footnote id="F3">Represents 1,266,000 shares of Common Stock held directly by the Managed Account and 1,136,792 held directly by Northern Right Capital (QP), L.P., a Texas limited partnership (&quot;Northern Right QP&quot;).</footnote>
        <footnote id="F4">As general partner and investment manager of Northern Right QP, Northern Right Management may be deemed to be the beneficial owner of the shares of Common Stock held by Northern Right QP.  As the investment manager of the Managed Account, Northern Right Management may also be deemed to be the beneficial owner of the shares of Common Stock held by the Managed Account.  As general partner of Northern Right Management, BC Advisors, LLC, a Texas limited liability company (&quot;BCA&quot;) may be deemed to be the beneficial owner of the shares of the Common Stock beneficially owned (or deemed beneficially owned) by Northern Right Management.  As the managing member of BCA, Mr. Drapkin may be deemed to be the beneficial owner of the shares of Common Stock beneficially owned (or deemed beneficially owned) by the BCA.  Pursuant to Rule 16a-1, Mr. Drapkin disclaims such beneficial ownership, except to the extent of his pecuniary interest therein.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Matthew A. Drapkin</signatureName>
        <signatureDate>2017-10-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
