Ma Dong-seok (마동석) is a South Korean actor. Born Lee Dong-seok on 1st March 1971, he is best known for his supporting roles in The Neighbor, Nameless Gangster, and The Unjust. He also played leading roles in Norigae, Murderer and One on One. Under his Westernized real name Don Lee and before he turned to acting, he was once the personal trainer of mixed martial artists Mark Coleman and Kevin Randleman.