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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-09-30</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001479613</rptOwnerCik>
            <rptOwnerName>Reese Jason W.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O IMPERIAL CAPITAL ASSET MANAGEMENT</rptOwnerStreet1>
            <rptOwnerStreet2>10100 SANTA MONICA BLVD., SUITE 2400</rptOwnerStreet2>
            <rptOwnerCity>LOS ANGELES</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90067</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001805378</rptOwnerCik>
            <rptOwnerName>Imperial Capital Asset Management, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>10100 SANTA MONICA BLVD., SUITE 2400</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LOS ANGELES</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90067</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001308057</rptOwnerCik>
            <rptOwnerName>LONG BALL PARTNERS LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O IMPERIAL CAPITAL ASSET MANAGEMENT</rptOwnerStreet1>
            <rptOwnerStreet2>10100 SANTA MONICA BLVD., SUITE 2400</rptOwnerStreet2>
            <rptOwnerCity>LOS ANGELES</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90067</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, par value $0.001 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2020-09-30</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>18538</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>73831</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common stock, par value $0.001 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2329312</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Jason Reese was awarded 18,538 restricted shares that fully vested on the grant date, September 30, 2020.</footnote>
        <footnote id="F2">The Common Stock is held directly by Long Ball Partners, LLC (&quot;Long Ball&quot;). Mr. Reese is portfolio manager to Long Ball and is Chairman and Chief Executive Officer of Imperial Capital Asset Management, LLC (&quot;ICAM&quot;), which is the managing member of and investment manager to Long Ball. Each of Mr. Reese and ICAM disclaims beneficial ownership of the securities held by Long Ball except to the extent of that person's pecuniary interest therein. Each of Long Ball and ICAM disclaims beneficial ownership of the securities held by Mr. Reese.</footnote>
    </footnotes>

    <remarks>Mr. Reese is a director and Executive Co-Chairman of the Issuer.
The Reporting Persons are jointly filing this Form 4.</remarks>

    <ownerSignature>
        <signatureName>Long Ball Partners, LLC, By: Imperial Capital Asset Management, LLC, its Managing Member, By: /s/ Jason Reese, Chairman &amp; CEO</signatureName>
        <signatureDate>2020-10-15</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Imperial Capital Asset Management, LLC, By: /s/ Jason Reese, Chairman &amp; CEO</signatureName>
        <signatureDate>2020-10-15</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Jason Reese, /s/ Jason Reese</signatureName>
        <signatureDate>2020-10-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
