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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2015-11-13</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>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2015-11-13</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>10000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>17.42</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2190738</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnotes</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2015-11-16</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>10000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>17.64</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>113195</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The price reported in Column 4 is a weighted average price.  These shares were purchased in multiple transactions.  The reported price for the share purchases made on November 13, 2015 is based on prices ranging from a low of $17.33 per share to a high of $17.49 per share.  The reported price for the share purchases made on November 16, 2015 is based on prices ranging from a low of $17.42 per share to a high of $17.79 per share.  The reporting person undertakes to provide to Solar Capital Ltd. (the &quot;Issuer&quot;), any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price set forth above.</footnote>
        <footnote id="F2">Includes 39,500 shares of the Issuer directly held by Michael S. Gross' profit sharing plan (the &quot;Profit Sharing Plan&quot;), 10,000 of which are reported as purchased on this Form 4.  Mr. Gross may be deemed to directly beneficially own these shares as the sole participant in the Profit Sharing Plan.  In addition, the total includes 20,000 shares of the Issuer held by a grantor retained annuity trust setup by and for Mr. Gross (the &quot;GRAT&quot;), which Mr. Gross may be deemed to directly beneficially own as the sole trustee of the GRAT.  Also includes 1,285,013 shares of the Issuer held by Solar Capital Investors, LLC (&quot;Solar Capital I&quot;) and 715,000 shares of the Issuer held by Solar Capital Investors II, LLC (&quot;Solar Capital II&quot;), a portion of both of which may be deemed to be indirectly beneficially owned by Mr. Gross, Bruce J. Spohler and the GRAT by virtue of their collective ownership interest therein.</footnote>
        <footnote id="F3">(Continued from Footnote (2)) Furthermore, the total includes 131,225 shares held by Solar Capital Partners Employee Stock Plan, LLC (the &quot;SCP Plan&quot;), which is controlled by Solar Capital Partners, LLC (&quot;Solar Capital Partners&quot;).  Mr. Gross and Mr. Spohler may be deemed to indirectly beneficially own a portion of the shares held by the SCP Plan by virtue of their collective ownership interest in Solar Capital Partners.  Mr. Gross disclaims beneficial ownership of any of the Issuer's securities directly held by Solar Capital I, Solar Capital II or the SCP Plan, except to the extent of his pecuniary interest therein, and this report shall not be deemed an admission that Mr. Gross is the beneficial owner of such securities for purposes of Section 16 or any other purpose.</footnote>
    </footnotes>

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

    <ownerSignature>
        <signatureName>/s/ Michael S. Gross</signatureName>
        <signatureDate>2015-11-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
