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

    <schemaVersion>X0407</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2023-03-28</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001653384</issuerCik>
        <issuerName>Runway Growth Finance Corp.</issuerName>
        <issuerTradingSymbol>RWAY</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001909657</rptOwnerCik>
            <rptOwnerName>Brookfield Multi-Strategy Master Fund LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>395 NINTH AVENUE, 52ND FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10001</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001937926</rptOwnerCik>
            <rptOwnerName>Brookfield Asset Management Ltd.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>BROOKFIELD PLACE, SUITE 300</rptOwnerStreet1>
            <rptOwnerStreet2>181 BAY ST. P.O. BOX 762</rptOwnerStreet2>
            <rptOwnerCity>TORONTO</rptOwnerCity>
            <rptOwnerState>A6</rptOwnerState>
            <rptOwnerZipCode>M5J 2T3</rptOwnerZipCode>
            <rptOwnerStateDescription>ONTARIO, CANADA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001962420</rptOwnerCik>
            <rptOwnerName>Brookfield Asset Management ULC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>BROOKFIELD PLACE, SUITE 300</rptOwnerStreet1>
            <rptOwnerStreet2>181 BAY ST. P.O. BOX 762</rptOwnerStreet2>
            <rptOwnerCity>TORONTO</rptOwnerCity>
            <rptOwnerState>A6</rptOwnerState>
            <rptOwnerZipCode>M5J 2T3</rptOwnerZipCode>
            <rptOwnerStateDescription>ONTARIO, CANADA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001504722</rptOwnerCik>
            <rptOwnerName>Brookfield US Holdings Inc.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>BROOKFIELD PLACE, SUITE 300</rptOwnerStreet1>
            <rptOwnerStreet2>181 BAY ST. P.O. BOX 762</rptOwnerStreet2>
            <rptOwnerCity>TORONTO</rptOwnerCity>
            <rptOwnerState>A6</rptOwnerState>
            <rptOwnerZipCode>M5J 2T3</rptOwnerZipCode>
            <rptOwnerStateDescription>ONTARIO, CANADA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001403525</rptOwnerCik>
            <rptOwnerName>Oaktree Capital Group Holdings GP, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O OAKTREE CAPITAL MANAGEMENT, L.P.</rptOwnerStreet1>
            <rptOwnerStreet2>333 SOUTH GRAND AVENUE, 28TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>LOS ANGELES</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90071</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001780629</rptOwnerCik>
            <rptOwnerName>Oaktree Opportunities Fund Xb Holdings (Delaware), L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>333 SOUTH GRAND AVENUE, 28TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LOS ANGELES</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90071</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001768973</rptOwnerCik>
            <rptOwnerName>Brookfield US Inc.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>BROOKFIELD PLACE, 15TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2>250 VESEY STREET</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10281</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001909269</rptOwnerCik>
            <rptOwnerName>Brookfield Public Securities Group Holdings LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>BROOKFIELD PLACE, 15TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2>250 VESEY STREET</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10281</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001760437</rptOwnerCik>
            <rptOwnerName>Brookfield BHS Advisors LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>395 NINTH AVENUE, 52ND FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10001</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001909267</rptOwnerCik>
            <rptOwnerName>Brookfield Multi-Strategy Fund GP LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>395 NINTH AVENUE, 52ND FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10001</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2023-03-28</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>24744</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>11.962</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>21104923</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                    <footnoteId id="F6"/>
                    <footnoteId id="F7"/>
                    <footnoteId id="F8"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2023-03-29</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>50256</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>11.935</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>21054667</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                    <footnoteId id="F6"/>
                    <footnoteId id="F7"/>
                    <footnoteId id="F8"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Includes shares acquired pursuant to the issuer's dividend reinvestment plan.</footnote>
        <footnote id="F2">Brookfield Multi-Strategy Master Fund LP, a Cayman Island exempted limited partnership (&quot;Master Fund LP&quot;), directly owns no shares of common stock (the &quot;Common Stock&quot;) of Runway Growth Finance Corp. (&quot;Issuer&quot;) following the transactions reported herein. OCM Growth Holdings, LLC, a Delaware limited liability company (&quot;LLC&quot;)(&quot;OCMGH&quot;), directly owns 21,030,578 shares of Common Stock of the Issuer. Oaktree opportunities Fund Xb Holdings (Delaware), L.P., a Delaware limited partnership (&quot;Fund Xb Delaware&quot;), directly owns 24,089 shares of Common Stock of the Issuer. This Form 4 is being filed by (i) Oaktree Fund GP, LLC, a Delaware LLC (&quot;GP LLC&quot;), in its capacity as manager of OCMGH and Fund Xb Delaware, (ii) Oaktree GP I, L.P., a Delaware limited partnership (&quot;GP I LLC&quot;), in its capacity as managing member of GP LLC, (iii) Oaktree Capital I, L.P., a Delaware limited partnership (&quot;Capital I&quot;), in its capacity as general partner of GP I,</footnote>
        <footnote id="F3">(Continued from Footnote 2) (iv) OCM Holdings I, LLC, a Delaware LLC (&quot;Holdings I&quot;), in its capacity as general partner of Capital I, (v) Oaktree Holdings, LLC, a Delaware LLC (&quot;Holdings&quot;),in its capacity as managing member of Holdings I; (vi) Oaktree Capital Group, LLC, a Delaware LLC (&quot;OCG&quot;), in its capacity as managing member of Holdings; and (vii) Oaktree Capital Group Holdings GP, LLC, a Delaware LLC (&quot;OCGH GP&quot;), in its capacity as the indirect owner of the class B units of OCG; (viii) Brookfield Multi-Strategy Fund GP LLC, a Delaware LLC (&quot;Multi-Fund Strategy Fund GP&quot;), in its capacity as general partner of Master Fund LP; (xi) Brookfield BHS Advisors, LLC, a Delaware LLC (&quot;BHS Advisors&quot;), in its capacity as investment manager to Master Fund LP; in its capacity as managing member of Holdings I; (vi) Oaktree Capital Group, LLC, a Delaware LLC (&quot;OCG&quot;), in its capacity as managing member of Holdings; and</footnote>
        <footnote id="F4">(Continued from Footnote 3) (vii) Oaktree Capital Group Holdings GP, LLC, a Delaware LLC (&quot;OCGH GP&quot;), in its capacity as the indirect owner of the class B units of OCG; (viii) Brookfield Multi-Strategy Fund GP LLC, a Delaware LLC (&quot;Multi-Fund
Strategy Fund GP&quot;), in its capacity as general partner of Master Fund LP; (xi) Brookfield BHS Advisors, LLC, a Delaware LLC (&quot;BHS Advisors&quot;), in its capacity as investment manager to Master Fund LP; (x) Brookfield Public Securities Group Holdings LLC, a Delaware LLC (&quot;Securities Group Holdings&quot;), in its capacity as managing manager of BHS Advisors; (xi) Brookfield US Inc., a Delaware corporation (&quot;Brookfield US&quot;), in its capacity as managing member of Securities Group Holdings; (xii) Brookfield US Holdings Inc., a Canadian corporation (&quot;Brookfield US Holdings&quot;), in its capacity as the 100% holder of Brookfield US's Class A Common Stock and 50% holder of Brookfield US's Class C Series 1 Preferred Shares;</footnote>
        <footnote id="F5">(Continued from Footnote 4) (xiii) Brookfield Asset Management ULC, a Canadian unlimited liability company (&quot;BAM ULC&quot;), in its capacity as the sole shareholder of Brookfield US Holdings; (xiv) Brookfield Corporation, a Canadian corporation (&quot;BAM&quot;), in its capacity as the indirect owner of the class A units of OCG and holder of 75% of BAM ULC; (xv) Brookfield Asset Management Ltd., a Canadian corporation (&quot;BAM Ltd.&quot;), in its capacity as holder of 25% of BAM ULC; and (xvi) BAM Partners Trust, a trust formed under the laws of Ontario, in its capacity as the sole owner of Class B Limited Voting Shares of BAM.</footnote>
        <footnote id="F6">Each Reporting Person disclaims beneficial ownership of all equity securities reported herein except to the extent of its respective pecuniary interest therein, and the filing of this Form 4 shall not be construed as an admission that any such Reporting Person is the beneficial owner of any equity securities covered by this Form 4.</footnote>
        <footnote id="F7">OCGH GP is managed by an executive committee consisting of Howard S. Marks, Bruce A. Karsh, Sheldon M. Stone, John B. Frank, and Jay S. Wintrob (the &quot;OCGH GP Members&quot;). In such capacity, the OCGH GP Members may be deemed to have indirect beneficial ownership of the Common Stock. Each OCGH GP Member expressly disclaims beneficial ownership of the Common Stock, except to the extent of his respective pecuniary interest therein, and the filing of this Form 4 shall not be construed as an admission that any such person is the beneficial owner of any equity securities covered by this Form 4.</footnote>
        <footnote id="F8">The Reporting Persons may be deemed directors by deputization by virtue of their right to designate representatives to be nominated by the Issuer to serve on the Issuer's board of directors.</footnote>
    </footnotes>

    <remarks>Form 2 of 2</remarks>

    <ownerSignature>
        <signatureName>Brookfield Multi-Strategy Master Fund LP, /s/ Bryan Gallagher, Legal Counsel</signatureName>
        <signatureDate>2023-03-30</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Oaktree Capital Group Holdings GP, LLC, /s/ Henry Orren, Senior Vice President</signatureName>
        <signatureDate>2023-03-30</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Brookfield US Inc., /s/ Kathy Sarpash, Secretary</signatureName>
        <signatureDate>2023-03-30</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Brookfield Public Securities Group Holdings LLC, /s/ Brian Hourihan, Regulatory Counsel and Chief Compliance Officer</signatureName>
        <signatureDate>2023-03-30</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Brookfield BHS Advisors LLC, /s/ Brian Hourihan, Managing Director, Chief Compliance Officer and Regulatory Counsel</signatureName>
        <signatureDate>2023-03-30</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Brookfield Multi-Strategy Fund GP LLC, /s/ Bryan Gallagher, Legal Counsel</signatureName>
        <signatureDate>2023-03-30</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Brookfield US Holdings Inc., /s/ Kathy Sarpash, Vice President and Secretary</signatureName>
        <signatureDate>2023-03-30</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Oaktree Opportunities Fund Xb Holdings (Delaware), L.P., By: Oaktree Fund GP, LLC Its: Manager, By: Oaktree Fund GP I, L.P. Its Managing Member, /s/ Henry Orren, Senior Vice President</signatureName>
        <signatureDate>2023-03-30</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Brookfield Asset Management Ltd., /s/ Kathy Sarpash, Secretary</signatureName>
        <signatureDate>2023-03-30</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Brookfield Asset Management ULC /s/ Kathy Sarpash, Secretary</signatureName>
        <signatureDate>2023-03-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
