Lee Dong-seok, better known by the stage name Ma Dong-seok (Korean: 마동석), or Don Lee is an American-born South Korean actor based in South Korea. With his breakout performance in Train to Busan (2016) and subsequent leading roles, he has become one of the most successful actors from South Korea. He was Gallup Korea's Film Actor of the Year in 2018.

Train to Busan is a 2016 South Korean action horror film directed by Yeon Sang-ho and starring Gong Yoo, Jung Yu-mi, Ma Dong-seok, Kim Su-an, Choi Woo-shik, Ahn So-hee and Kim Eui-sung. The film mostly takes place on a KTX from Seoul to Busan as a zombie apocalypse suddenly breaks out in the country and threatens the safety of the passengers.