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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-08-18</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001854863</issuerCik>
        <issuerName>Blue Whale Acquisition Corp I</issuerName>
        <issuerTradingSymbol>BWCA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001874580</rptOwnerCik>
            <rptOwnerName>Blue Whale Sponsor I LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>PO BOX 1093, BOUNDARY HALL</rptOwnerStreet1>
            <rptOwnerStreet2>CRICKET SQUARE</rptOwnerStreet2>
            <rptOwnerCity>GRAND CAYMAN</rptOwnerCity>
            <rptOwnerState>E9</rptOwnerState>
            <rptOwnerZipCode>KY1-1102</rptOwnerZipCode>
            <rptOwnerStateDescription>CAYMAN ISLANDS</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001875491</rptOwnerCik>
            <rptOwnerName>Kokko Kevin</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>PO BOX 1093, BOUNDARY HALL</rptOwnerStreet1>
            <rptOwnerStreet2>CRICKET SQUARE</rptOwnerStreet2>
            <rptOwnerCity>GRAND CAYMAN</rptOwnerCity>
            <rptOwnerState>E9</rptOwnerState>
            <rptOwnerZipCode>KY1-1102</rptOwnerZipCode>
            <rptOwnerStateDescription>CAYMAN ISLANDS</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001775215</rptOwnerCik>
            <rptOwnerName>MIC Capital Partners (Public) Parallel Cayman, LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O WALKERS CORPORATE LIMITED. 190</rptOwnerStreet1>
            <rptOwnerStreet2>ELGIN AVENUE, GEORGE TOWN,</rptOwnerStreet2>
            <rptOwnerCity>GRAND CAYMAN</rptOwnerCity>
            <rptOwnerState>E9</rptOwnerState>
            <rptOwnerZipCode>KY1-9008</rptOwnerZipCode>
            <rptOwnerStateDescription>CAYMAN ISLANDS</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Class F ordinary Shares</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2021-08-18</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>326757</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Ordinary Shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>326757</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2500979</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F6"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Class G ordinary shares</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F4"/>
                <footnoteId id="F5"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2021-08-18</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F4"/>
                <footnoteId id="F5"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>653513</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F4"/>
                <footnoteId id="F5"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F4"/>
                <footnoteId id="F5"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Ordinary Shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>653513</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5097958</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F6"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">As described in the issuer's registration statement on Form S-1 (File No. 333-257816) under the heading &quot;Description of Securities--Founder Shares,&quot; on the first business day following the closing of the issuer's initial business combination, the Class F ordinary shares will automatically convert into a number of Class A ordinary shares at a ratio such that the number of Class A ordinary shares issuable upon conversion of all Class F ordinary shares will equal, in the aggregate on an as-converted basis, equal to 10% of the sum of (i) the total number of all Class A ordinary shares issued and outstanding upon completion of this the issuer's initial public offering (&quot;IPO&quot;) (including any over-allotment shares if the underwriters exercise their over-allotment option and without giving effect to any redemptions of any public shares in connection with the initial business combination), (continued in footnote (2))</footnote>
        <footnote id="F2">plus (ii) the total number of Class A ordinary shares issued or deemed issued or issuable upon conversion of the Class F founder ordinary shares, plus (iii) unless waived by Blue Whale Sponsor I LLC (the &quot;Sponsor&quot;), the total number of Class A ordinary shares or equity-linked securities exercisable for or convertible into Class A ordinary shares issued, deemed issued, or to be issued, in connection with or in relation to the consummation of the initial business combination, including any forward purchase shares, and excluding (x) any Class A ordinary shares or equity-linked securities exercisable for or convertible into Class A ordinary shares issued, deemed issued, or to be issued, to any seller in the initial business combination and (y) any Class A ordinary shares issuable upon conversion of the Class G founder shares.</footnote>
        <footnote id="F3">On August 16, 2021, the underwriters partially exercised the over-allotment option and purchased an additional 2,940,811 units from the issuer, generating gross proceeds of $29,408,110 and resulting in the issuance of an additional 326,757 Class F ordinary shares. If calculated based on the public shares outstanding as of immediately after the closing of the over-allotment option on August 18, 2021, the Class F ordinary shares would be convertible (on the first day following the completion of the issuer's business combination) into an aggregate of 2,500,979 Class A ordinary shares.</footnote>
        <footnote id="F4">The Class G ordinary shares will convert into Class A ordinary shares after the issuer's initial business combination, subject to adjustment pursuant to certain anti-dilution rights, but only to the extent certain triggering events occur prior to the applicable anniversary of the issuer's initial business combination including three triggering events based on the issuer's Class A ordinary shares trading at $15.00 (prior to the 3rd year anniversary), $20.00 (prior to the 6th year anniversary) and $25.00 (prior to the 9th year anniversary) per share following the closing of the issuer's initial business combination (continued in footnote (5))</footnote>
        <footnote id="F5">and also upon any liquidation, merger, share exchange, reorganization or other similar transaction. Notwithstanding the foregoing, all Class G ordinary shares that are issued and outstanding on the applicable anniversary of the issuer's initial business combination will be automatically forfeited. On August 16, 2021, the underwriters partially exercised the over-allotment option and purchased an additional 2,940,811 units from the issuer, generating gross proceeds of $29,408,110 and resulting in the issuance of an additional 653,513 Class G ordinary shares. If calculated based on the public shares outstanding as of immediately after the closing of the over-allotment option on August 18, 2021, the Class G ordinary shares would be convertible into an aggregate of 5,097,958 Class A ordinary shares.</footnote>
        <footnote id="F6">Kevin Kokko is the manager of the Sponsor, and MIC Capital Partners (Public) Parallel Cayman, LP (&quot;MIC Capital Partners&quot;) is the parent of the Sponsor. By virtue of these relationships, each of Kevin Kokko and MIC Capital Partners may be deemed a beneficial owner of the shares held by the Sponsor. Each of Kevin Kokko and MIC Capital Partners disclaims beneficial ownership of such shares, except to the extent of his or its pecuniary interest therein.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Blue Whale Sponsor I LLC, By: /s/ Kevin Kokko</signatureName>
        <signatureDate>2021-08-20</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Kevin Kokko, By: /s/ Kevin Kokko</signatureName>
        <signatureDate>2021-08-20</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>MIC Capital Partners, (Public) Parallel Cayman, LP, By: /s/ Rodney Cannon</signatureName>
        <signatureDate>2021-08-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
