X0306 4 2021-01-04 0 0001315257 Koppers Holdings Inc. KOP 0001806249 Apostolou Stephanie L 436 SEVENTH AVENUE PITTSBURGH PA 15219 0 1 0 0 General Counsel & Secretary Common Stock 2021-01-04 4 A 0 5026 0.00 A 19669.8708 D The reporting person was awarded time-based restricted stock units on January 4, 2021, which will vest in annual installments of 25 percent over four years. Includes 1,278 shares of Koppers Holdings Inc. common stock acquired pursuant to the Koppers Holdings Inc. Employee Stock Purchase Plan on March 31, 2020, June 30, 2020 and September 30, 2020. These acquisitions were exempt under both Rule 16b-3(c) and Rule 16b-3(d). /s/Stephanie L. Apostolou 2021-01-06