Terrance Quinn (born July 15, 1952), known professionally as Terry O'Quinn, is an American actor. He is best known for his Emmy Award-winning performance as John Locke on the TV series Lost (2004–2010). He had roles in films including The Stepfather (1987), The Rocketeer (1991), Heaven's Gate (1980), Silver Bullet (1985), Young Guns (1988), Blind Fury (1989), Tombstone (1993) and Primal Fear (1996).