Terrance Quinn (born July 15, 1952), known professionally as Terry O'Quinn, is an American actor. He played John Locke on the TV series Lost (2004), the title role in The Stepfather (1987) and Stepfather II: Make Room for Daddy (1989), and Peter Watts in Millennium (1996), which ran for three seasons (1996-1999). He has also hosted Mysteries of The Missing on The Science Channel.
O'Quinn was born at War Memorial Hospital in Sault Ste. Marie, Michigan, one of 11 siblings, and grew up in nearby Newberry, Michigan. He is of Irish and English descent, 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.
In the 1970s he came to Baltimore to act in the Center Stage production of Tartuffe. He remained at Center Stage for some years and often appeared with the late Tana Hicken, most notably as Ben