UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE FISCAL YEAR ENDED DECEMBER 31, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO f COMMISSION FILE NUMBER 1-4825 WEYERHAEUSER COMPANY A WASHINGTON CORPORATION 91-0470860 (IRS EMPLOYER IDENTIFICATION NO.) 220 OCCIDENTAL AVENUE SOUTH, SEATTLE, WASHINGTON ...