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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-02-27</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001660734</issuerCik>
        <issuerName>Triton International Ltd</issuerName>
        <issuerTradingSymbol>TRTN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001617520</rptOwnerCik>
            <rptOwnerName>Warburg Pincus (Ganymede-II) Private Equity X, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O WARBURG PINCUS LLC</rptOwnerStreet1>
            <rptOwnerStreet2>450 LEXINGTON</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10017</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000929408</rptOwnerCik>
            <rptOwnerName>WARBURG PINCUS &amp; CO.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>450 LEXINGTON AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>NEW YORK</rptOwnerStreet2>
            <rptOwnerCity>NY</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>100173147</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001162870</rptOwnerCik>
            <rptOwnerName>WARBURG PINCUS LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>450 LEXINGTON AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10017</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001617568</rptOwnerCik>
            <rptOwnerName>ICIL Triton Holdings, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O WARBURG PINCUS LLC</rptOwnerStreet1>
            <rptOwnerStreet2>450 LEXINGTON</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10017</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001617567</rptOwnerCik>
            <rptOwnerName>WP Triton Manager Ltd.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O WARBURG PINCUS LLC</rptOwnerStreet1>
            <rptOwnerStreet2>450 LEXINGTON</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10017</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001239318</rptOwnerCik>
            <rptOwnerName>KAYE CHARLES R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O WARBURG PINCUS LLC</rptOwnerStreet1>
            <rptOwnerStreet2>450 LEXINGTON AVENUE</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10017</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001220638</rptOwnerCik>
            <rptOwnerName>Landy Joseph P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O WARBURG PINCUS LLC</rptOwnerStreet1>
            <rptOwnerStreet2>450 LEXINGTON AVENUE</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10017</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2017-02-27</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>7877590</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>11816382</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                    <footnoteId id="F6"/>
                    <footnoteId id="F7"/>
                    <footnoteId id="F8"/>
                    <footnoteId id="F9"/>
                    <footnoteId id="F10"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">On July 12, 2016, TAL International Group, Inc., a Delaware corporation (&quot;TAL&quot;), Triton International Limited, a Bermuda exempted company (the &quot;Issuer&quot;), Triton Container International Limited, a Bermuda exempted company (&quot;Triton&quot;), Ocean Delaware Sub, Inc., a Delaware corporation and direct wholly owned subsidiary of the Issuer (&quot;Delaware Merger Sub&quot;), and Ocean Bermuda Sub Limited, a Bermuda exempted company and direct wholly owned subsidiary of the Issuer (&quot;Bermuda Merger Sub&quot;), completed the transactions contemplated by the Transaction Agreement, dated as of November 9, 2015, by and among TAL, the Issuer, Triton, Delaware Merger Sub and Bermuda Merger Sub, pursuant to which, ICIL Triton Holdings, L.P., a Bermuda exempted limited partnership (&quot;ICIL-Triton&quot;), received 7,877,590 common shares of the Issuer (the &quot;Common Shares&quot;).</footnote>
        <footnote id="F2">On February 27, 2017, ICIL-Triton distributed the Common Shares to its limited partner in connection with a pro rata distribution to its partners.</footnote>
        <footnote id="F3">Additional shareholders of the Issuer that are reporting persons are (i) Warburg Pincus X Partners, L.P., a Delaware limited partnership (&quot;WP X Partners&quot;), (ii) Warburg Pincus (Callisto-II) Private Equity X, L.P., a Delaware limited partnership (&quot;WP Callisto-II&quot;), (iii) Warburg Pincus (Europa-II) Private Equity X, L.P., a Delaware limited partnership (&quot;WP Europa-II&quot;), and (iv) Warburg Pincus (Ganymede-II) Private Equity X, L.P., a Delaware limited partnership (&quot;WP Ganymede-II&quot;, and together with WP X Partners, WP Callisto-II and WP Europa-II, the &quot;WP Shareholders&quot;).</footnote>
        <footnote id="F4">Warburg Pincus (Europa) X LLC, a Delaware limited liability company (&quot;WP Europa&quot;), is the general partner of WP Europa II. Warburg Pincus (Ganymede) X LLC, a Delaware limited liability company (&quot;WP Ganymede&quot;), is the general partner of WP Ganymede II. Warburg Pincus X, L.P., a Delaware limited partnership (&quot;WP X LP&quot;), is (i) the general partner of WP X Partners and WP Callisto-II, and (ii) the managing member of WP Europa and WP Ganymede. Warburg Pincus X GP L.P., a Delaware limited partnership (&quot;WP X GP&quot;), is the general partner of WP X LP. WPP GP LLC, a Delaware limited liability company (&quot;WPP GP&quot;), is the general partner of WP X GP.</footnote>
        <footnote id="F5">Warburg Pincus Partners, L.P., a Delaware limited partnership (&quot;WP Partners&quot;), is the managing member of WPP GP. Warburg Pincus Partners GP LLC, a Delaware limited liability company (&quot;WPP GP LLC&quot;), is the general partner of WP Partners. Warburg Pincus &amp; Co., a New York general partnership (&quot;WP&quot;), is the managing member of WPP GP LLC. Warburg Pincus LLC, a New York limited liability company (&quot;WP LLC&quot;, and together with the WP Shareholders, WP Europa, WP Ganymede, WP X LP, WP X GP, WPP GP, WP Partners, WPP GP LLC and WP, the &quot;Warburg Pincus Entities&quot;), is the manager of the WP Shareholders. WP Triton Manager Ltd., a Bermuda exempted company (&quot;WP Triton Manager&quot;), is the general partner of ICIL-Triton.</footnote>
        <footnote id="F6">Charles R. Kaye and Joseph P. Landy (Messrs. Kaye and Landy, together with the Warburg Pincus Entities, ICIL-Triton and WP Triton Manager, the &quot;Warburg Pincus Reporting Persons&quot;) are each a (i) Managing General Partner of WP and (ii) Managing Member and Co-Chief Executive Officer of WP LLC, and may be deemed to control the Warburg Pincus Entities and be the beneficial owners of the Common Shares held by the WP Shareholders.</footnote>
        <footnote id="F7">Pursuant to Rule 16a-1(a)(4) of the Exchange Act of 1934, as amended (the &quot;Exchange Act&quot;), each of the Warburg Pincus Reporting Persons, other than ICIL-Triton and the WP Shareholders, herein states that this Form 4 shall not be deemed an admission that it or he is the beneficial owner of any of the Common Shares of the Issuer reported in this Form 4. Each of WP Triton Manager, WP Europa, WP Ganymede, WP X LP, WP X GP, WPP GP, WP Partners, WPP GP LLC, WP, WP LLC and Messrs. Kaye and Landy disclaims beneficial ownership of the Common Shares of the Issuer, except to the extent of its or his pecuniary interest in such Common Shares.</footnote>
        <footnote id="F8">Information with respect to each Warburg Pincus Reporting Person is given solely by such Warburg Pincus Reporting Person, and none of the Warburg Pincus Reporting Persons has responsibility for the accuracy or completeness of information supplied by another of the Warburg Pincus Reporting Persons.</footnote>
        <footnote id="F9">Solely for the purposes of Section 16 of the Exchange Act, each of the WP Shareholders, WP Europa, WP Ganymede, WP X LP, WP X GP, WPP GP, WP Partners, WPP GP LLC, WP, ICIL-Triton and WP Triton Manager may be deemed a director-by-deputization by virtue of their contractual right to appoint one or more directors to the board of directors of the Issuer, pursuant to that certain Sponsor Shareholders Agreement (Warburg Pincus), by and among the Issuer and the shareholders party thereto, dated as of November 9, 2015, as amended.</footnote>
        <footnote id="F10">Because no more than 10 reporting persons can file any one Form 4 through the Securities and Exchange Commission's EDGAR system, Warburg Pincus (Europa-II) Private Equity X, L.P., Warburg Pincus Partners GP LLC, Warburg Pincus (Callisto-II) Private Equity X, L.P., Warburg Pincus X Partners, L.P., Warburg Pincus (Europa) X LLC, Warburg Pincus (Ganymede) X LLC, Warburg Pincus X, L.P., Warburg Pincus X GP L.P., WPP GP LLC and Warburg Pincus Partners, L.P. have made a separate Form 4 filing.</footnote>
    </footnotes>

    <remarks>(11) The Reporting Persons are jointly filing this Form 4 pursuant to Rule 16a-3(j) under the Exchange Act.</remarks>

    <ownerSignature>
        <signatureName>See Exhibit 99.1 (11)</signatureName>
        <signatureDate>2017-02-27</signatureDate>
    </ownerSignature>
</ownershipDocument>
