Terry O'Quinn (born Terrance Quinn; July 15, 1952) is an American actor, most famous for playing John Locke on the TV series Lost. He made his debut in a 1980 television movie called F.D.R.: The Last Year. Since then, O'Quinn has had minor supporting roles in films and TV movies such as Young Guns, All the Right Moves, Silver Bullet, Places in the Heart, Between Two Women, and The Rocketeer, in which he portrayed Howard Hughes. O'Quinn has had guest roles on TV shows such as Miami Vice, The Twilight Zone, Tales of the Unexpected, The West Wing, JAG, Remington Steele, and The X Files.
O'Quinn became known for playing the title role in The Stepfather and Stepfather II, and in 1996 O'Quinn was cast as Peter Watts in Millennium, which ran for three seasons (1996–1999). In 2004, O'Quinn finally broke into mainstream popularity after landing the role of John Locke on the ABC TV series Lost, for which he won an Emmy Award in 2007 and was nominated in 2005 and 2010.
O'Quinn was born as Terrance Quinn at War Memorial Hospital in Sault Ste. Marie, Michigan, one of 11 siblings born to Irish American parents. He grew up in nearby Newberry, Michigan, and was raised Roman Catholic. He attended Central Michigan University in Mount Pleasant, Michigan, and the University of Iowa in Iowa City. He changed his surname from Quinn to O'Quinn as another registered actor already had the name Terrance Quinn.