UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q (Mark One) Quarterly Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 ☒ For the Quarterly Period Ended September 30, 2023. 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: 001-32504 TreeHouse Foods, Inc. (Exact name of the registrant as specified in its charter) Delaware 20-2311383 (State or other ...