Business Combination Prospectus (Form 425)

Filed by Criteo S.A. pursuant to

Rule 425 under the Securities Act of 1933

and deemed filed pursuant to Rule 14a-12

under the Securities Exchange Act of 1934

Subject Company: Criteo S.A.

Commission File No.: 001-36153

The following is being mailed to holders of Criteo's ordinary shares in connection with the general meeting of shareholders.

Paris, January 22, 2026

Dear Shareholder,

We are pleased to hereby inform you that you are convened to the general meeting of the shareholders of Criteo S.A. (the "Company") to be held on February 27, 2026, at 10:00 a.m., Paris time (the "General Meeting"), at the Company's registered office at 32 Rue Blanche, 75009 Paris, France, for the purposes set forth on the enclosed agenda, in connection with the proposed redomiciliation of the Company from France to Luxembourg.

Accompanying this convening notice is a proxy statement / prospectus providing details that should be reviewed and considered prior to voting at the General Meeting. We have also filed, and may further file, additional materials in connection with the proposed redomiciliation with the Securities and Exchange Commission, which can be accessed free of charge through the website maintained by the SEC at https://www.sec.gov, and/or the Company's investor relations website at https://criteo.investorroom.com. We encourage you to read the proxy statement / prospectus and such other materials carefully and in their entirety because they contain important information about the Company and the matters to be voted upon at the General Meeting.

Also enclosed herewith are (i) a proxy card, (ii) the full text of the draft resolutions to be voted upon at the General Meeting, and (iii) a summary of Criteo's situation during the past fiscal year.

In addition, any documents that must be made available to the shareholders pursuant to French law will be available, within the legal time period, upon email request sent to [email protected], together with a proof of a shareholding certificate. You may also, upon a single request, receive the abovementioned documents in connection with any future general meeting. There is no charge for requesting and receiving a copy of such documents. Please make the request as instructed on or before February 13, 2026 to facilitate timely delivery.

In accordance with the Company's by-laws, the Company's board of directors has fixed the record date for the General Meeting on February 25, 2026 at 00:00 (Paris time), meaning that only shareholders of record at that time are entitled to vote at the General Meeting. You have the right to (i) vote at the General Meeting, (ii) vote in advance by submitting your voting card by mail, (iii) grant your voting proxy directly to the chairperson of the General Meeting, or (iv) grant your voting proxy to another shareholder, your spouse or your partner with whom you have entered into a civil union, provided in each case that you are the holder of record of ordinary shares of the Company on the record date. You may ultimately decide to vote in person at the General Meeting by requesting an admission card by checking the appropriate box on your proxy card. If you choose to vote by mail, your proxy card must be received by Uptevia by February 23, 2026, in order to be taken into account. If you cast your vote by appointing the chairperson of the General Meeting as your proxy, the chairperson of the General Meeting will vote your ordinary shares in accordance with the Company's board of directors' recommendations. If you appoint another shareholder, your spouse or your partner with whom you are in a civil union to act as your proxy, such proxy must be written and made known to the Company, and such person's proxy must be received by Uptevia, by February 23, 2026 in order to be taken into account.

Whether or not you plan to attend the General Meeting in person, it is important that your shares be represented and voted. Please complete the enclosed proxy card and return it to the following address:

Uptevia

90 - 110 Esplanade du Général de Gaulle

92931 Paris La Défense Cedex

You can also submit questions during the General Meeting and in advance of the meeting. Questions submitted in advance of the General Meeting must be sent to the Company in written form no later than February 23, 2026 to the attention of the Chief Executive Officer of the Company, either by mail sent with acknowledgment of receipt to the Company's registered office or by email to [email protected], in each case accompanied with proof of a shareholding certificate. At management's discretion, proper questions raised in advance of the meeting in accordance with these procedures will be addressed by the Company during the General Meeting.

Finally, note that all information regarding the General Meeting can be found online on the Company's Investor Relations website: http://criteo.investorroom.com/annuals.

Yours sincerely,

Frederik van der Kooi

For the Board of Directors

Chairperson of the Board of Directors

Disclaimers

Cautionary Statement Regarding Forward-Looking Statements

This communication contains certain forward-looking statements within the meaning of the U.S. federal securities laws. Forward-looking statements include statements with respect to our financial condition, results of operations, cash flows, plans, objectives, future performance and business and the assumptions underlying such statements. By way of illustration, words such as "anticipate", "believe", "expect", "intend", "estimate", "project", "will", "should", "could", "may", "predict" and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain such identifying words. We base forward-looking statements on our current assumptions, expectations, estimates and projections about us and the markets that we serve in light of our industry experience, as well as our perception of historical trends, current conditions, expected future developments and other factors that we believe are appropriate under the circumstances. Forward-looking statements are not guarantees of future performance and involve risks, uncertainties, estimates and assumptions that are difficult to predict and often outside of our control. Therefore, actual outcomes and results may differ materially from those expressed in forward-looking statements. These forward-looking statements are subject to risks, uncertainties and other factors, including, among others: failure to obtain the required shareholder vote to adopt the proposals needed to complete the proposed redomiciliation; failure to satisfy any of the other conditions to the proposed redomiciliation, including the condition that the option to withdraw shares for cash in connection with the proposed redomiciliation is not exercised above a certain threshold; the proposed redomiciliation not being completed; the impact or outcome of any legal proceedings or regulatory actions that may be instituted against us in connection with the proposed redomiciliation; failure to list our shares on Nasdaq following the proposed redomiciliation or maintain our listing thereafter; inability to take advantage of the potential strategic opportunities provided by, and realize the potential benefits of, the proposed redomiciliation; the disruption of current plans and operations by the proposed redomiciliation; the disruption to our relationships, including with employees, landowners, suppliers, lenders, partners, governments and shareholders; the future financial performance of Criteo following the proposed redomiciliation, including our anticipated growth rate and market opportunity; changes in shareholders' rights as a result of the proposed redomiciliation; inability to terminate the deposit agreement and withdraw our ordinary shares from the depositary so as to terminate our ADS program; difficulty in adapting to operating under the laws of Luxembourg; the deferment or abandonment of the proposed redomiciliation by our board of directors up to three days prior to the general shareholders' meeting to vote thereon; following the completion of the proposed redomiciliation, a delay or failure in our ability to redomicile to the United States via the merger into a newly incorporated and wholly-owned U.S. subsidiary for any reason; costs or taxes related to the proposed redomiciliation; changes in general political, economic and competitive conditions and specific market conditions; adverse changes in the marketing industry; changes in applicable laws or accounting practices; failure related to our technology and our ability to innovate and respond to changes in technology; uncertainty regarding our ability to access a consistent supply of internet display advertising inventory and expand access to such inventory; investments in new business opportunities and the timing of these investments; whether the projected benefits of the proposed redomiciliation, acquisitions or other strategic transactions materialize as expected; uncertainty regarding our international operations and expansion, including related to changes in a specific country's or region's political or economic conditions or policies (such as changes in or new tariffs); the impact of competition; uncertainty regarding legislative, regulatory or self-regulatory developments regarding data privacy matters and the impact of efforts by other participants in our industry to comply therewith; our ability to obtain and utilize certain data as a result of consumer concerns regarding data collection and sharing, as well as potential limitations in accessing data from third parties; failure to enhance our brand cost-effectively; recent growth rates not being indicative of future growth; our ability to manage growth, potential fluctuations in operating results; our ability to grow our base of clients; risks related to future opportunities and plans, including the uncertainty of expected future financial performance and results; and those risks detailed from time-to-time under

the caption "Risk Factors" and elsewhere in Criteo's filings with the U.S. Securities and Exchange Commissions (the "SEC") and reports, including the Criteo's Annual Report on Form 10-K for the fiscal year ended December 31, 2024, filed with the SEC on February 28, 2025, subsequent Quarterly Reports on Form 10-Q and the Registration Statement on Form S-4 filed on November 3, 2025 and post-effective amendment thereto filed on January 7, 2026 in connection with the proposed redomiciliation, as well as the enclosed proxy statement / prospectus and any future filings and reports by Criteo. As a result of these and other factors, no assurance can be given as to our future results and achievements. Accordingly, a forward-looking statement is neither a prediction nor a guarantee of future events or circumstances and those future events or circumstances may not occur. You should not place undue reliance on the forward-looking statements, which speak only as of the date of this communication. We are under no obligation, and we expressly disclaim any obligation, to update or alter any forward-looking statements, whether as a result of new information, future events, or otherwise.

Additional Information and Where to Find It

A proxy statement / prospectus and other relevant documents are enclosed herewith and/or made or will be made available to Criteo's shareholders as of the record date. Criteo may also file other relevant documents with the SEC regarding the proposed redomiciliation. This communication is not a substitute for the registration statements, the proxy statement / prospectus or any other document that Criteo may file with the SEC with respect to the proposed redomiciliation. INVESTORS AND SECURITY HOLDERS ARE URGED TO READ THE REGISTRATION STATEMENT, THE PROXY STATEMENT / PROSPECTUS, ANY AMENDMENTS OR SUPPLEMENTS TO THOSE DOCUMENTS AND ANY OTHER RELEVANT DOCUMENTS THAT MAY BE FILED WITH THE SEC IF AND WHEN THEY BECOME AVAILABLE CAREFULLY AND IN THEIR ENTIRETY BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT CRITEO AND THE PROPOSED REDOMICILIATION.

Shareholders will be able to obtain copies of these materials (if and when they are available) and other documents containing important information about Criteo and the proposed redomiciliation, once such documents are filed with the SEC, free of charge through the website maintained by the SEC at www.sec.gov. Copies of documents filed with the SEC by Criteo are made available free of charge on Criteo's investor relations website at https://criteo.investorroom.com.

No Offer or Solicitation

This communication is for informational purposes only and is not intended to and does not constitute, or form part of, an offer, invitation or the solicitation of an offer or invitation to purchase, otherwise acquire, subscribe for, sell or otherwise dispose of any securities, or the solicitation of any vote or approval in any jurisdiction, pursuant to the proposed redomiciliation or otherwise, nor shall there be any sale, issuance or transfer of securities in any jurisdiction in contravention of applicable law.

Participants in the Solicitation

Criteo and its directors and certain of its executive officers and other employees may be deemed to be participants in the solicitation of proxies from Criteo's shareholders in connection with the proposed redomiciliation. Information about Criteo's directors and executive officers is set forth in the proxy statement for Criteo's 2025 Annual Meeting of Shareholders, which was filed with the SEC on April 29, 2025. Investors may obtain additional information regarding the interest of such participants by reading the proxy statement / prospectus and other relevant materials regarding the proposed redomiciliation to be filed with the SEC when they become available. These documents can be obtained free of charge from the sources indicated above in "Additional Information and Where to Find It."

RESOLUTIONS SUBMITTED TO THE GENERAL MEETING

OF FEBRUARY 27, 2026

The general meeting of Criteo (the "Company" or "French Criteo") (the "General Meeting") is convened specifically for the following purposes (the "Proposals"):

The approval of each of the Conversion Proposal, Charter Proposal, Auditor Proposal and Delegation Proposal is conditioned on the approval of the others.