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

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2024-07-25</periodOfReport>

    <issuer>
        <issuerCik>0001929589</issuerCik>
        <issuerName>MariaDB plc</issuerName>
        <issuerTradingSymbol>MRDB</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001974416</rptOwnerCik>
            <rptOwnerName>McCarthy Conor</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>699 VETERANS BLVD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>REDWOOD CITY</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94063</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>true</isOfficer>
            <officerTitle>Chief Financial Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>false</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Ordinary Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2024-07-25</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>61669</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.55</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Ordinary Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2024-07-25</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>375000</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.55</value>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The reported securities were tendered pursuant to the unsolicited offer (the &quot;Offer&quot;) by Meridian BidCo LLC, a Delaware limited liability company, an affiliate of K1 Investment Management, LLC, a Delaware limited liability company, to purchase all of the issued and to be issued ordinary shares of $0.01 each (nominal value) of MariaDB plc (each a &quot;MariaDB Share&quot;). These MariaDB Shares were tendered for purchase pursuant to the Offer and converted into the right to receive $0.55 in cash per MariaDB Share.</footnote>
        <footnote id="F2">Represents outstanding restricted stock unit awards (&quot;RSUs&quot;).</footnote>
        <footnote id="F3">Pursuant to the closing of the Offer, each outstanding RSU whether vested or unvested was cancelled and automatically converted into the right to receive $0.55 in cash per MariaDB Share issuable in settlement of such RSU immediately before the closing of the Offer, net of any withholding taxes required to be deducted and withheld by applicable law.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Conor McCarthy</signatureName>
        <signatureDate>2024-07-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
