UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 for the Fiscal Year Ended December 31, 2018 or ¨ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 for the transition period from to Commission file number: 001-36153 Criteo S.A. (Exact name of registrant as specified in its charter) France (State or other jurisdiction of incorporation or org ...