Washington D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE QUARTERLY PERIOD ENDED JUNE 30, 2025 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: 0-25837 HEIDRICK & STRUGGLES INTERNATIONAL, INC. (Exact Name of Registrant as Specified in its Charter) UNITED STATES SECURITIES AND EXCHANGE COMMISSION (State or Other Jurisdic ...