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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-03-09</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001418076</issuerCik>
        <issuerName>Solar Capital Ltd.</issuerName>
        <issuerTradingSymbol>SLRC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001186884</rptOwnerCik>
            <rptOwnerName>GROSS MICHAEL S</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SOLAR CAPITAL LTD.,</rptOwnerStreet1>
            <rptOwnerStreet2>500 PARK AVENUE</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>See Remarks</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2017-03-09</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>83903.5298</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock, par value $0.01 per share</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>83903.5298</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>83903.5298</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Grants of new restricted stock units (&quot;RSUs&quot;) with respect to 83,903.5298 shares held by Solar Capital Partners Employee Stock Plan, LLC (the &quot;SCP Plan&quot;) to certain of Solar Capital Partners, LLC's employees pursuant to Restricted Stock Unit Agreements, dated March 9, 2017. Shares of the common stock of Solar Capital Ltd. (the &quot;Issuer&quot;) underlying the RSUs are scheduled to vest in installments of 50% on March 1, 2019 and 50% on March 1, 2020. Upon settlement, the RSUs will become payable on a one-for-one basis in shares of the Issuer's common stock or the cash value thereof at the election of the SCP Plan administrators, Michael S. Gross and Bruce J. Spohler.</footnote>
        <footnote id="F2">Pursuant to the SEC staff no-action letters to Carlyle GMS Finance, Inc. (pub. Avail. Oct. 8, 2015) and to Babson Capital Management LLC (pub. Avail. Dec. 14, 2006), an employee benefit plan sponsored by an investment adviser (or an affiliated person of an investment adviser) to a closed-end investment company that has elected to be regulated as a business development company or to a closed-end investment company registered under the Investment Company Act of 1940, as amended, respectively, in either case that offers plan participants equity securities of such investment company is considered an &quot;employee benefit plan sponsored by the issuer&quot; for the purposes of Rule 16b-3 under the Securities Exchange Act of 1934, as amended.</footnote>
    </footnotes>

    <remarks>Chief Executive Officer, President, Chairman of the Board</remarks>

    <ownerSignature>
        <signatureName>/s/ Michael S. Gross</signatureName>
        <signatureDate>2017-03-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
