The versatile character actor has worked consistently for three decades, but few knew his name until he landed on Lost in 2004 as mysterious castaway John Locke. O'Quinn launched his acting career in the late 1970s and appeared in a wide array of films, plays and TV projects. His first movie role was in Michael Cimino's notorious 1980 flop Heaven's Gate. He survived that debacle and went on to the popular soap The Doctors, then to Broadway with Faye Dunaway in The Curse of an Aching Heart. Substantial supporting roles followed, but it was his villainous turn as the title character in the 1987 horror flick The Stepfather that proved he had a lead's charisma. However, the 1990s brought more meaty supporting roles and few lead ones. But it was during this time that he met X-Files creator Chris Carter, who cast O'Quinn in a couple of episodes of the hit series (and in the 1998 feature film), leading to prominent roles in Carter's Harsh Realm and Millennium series. Next, J.J. Abrams locked onto O'Quinn and inserted him into The West Wing and Alias. Then, Abrams did something rare in Hollywood: He offered O'Quinn a major role in his next series, Lost, without an audition. O'Quinn accepted, and he and his wife moved to Hawaii. The role led to O'Quinn's first Emmy nod in 2005 and first victory in 2007.
- Decided he wanted to be an actor at age 15 after seeing Franco Zeffirelli's Romeo and Juliet.
- Has been bald since his early 20s.
- Real name is Terrence Quinn; added the "O'" to distinguish himself from another actor named Terry Quinn.
- His future wife taught him how to ride a horse for his film debut in Heaven's Gate.
- Played Howard Hughes in the 1991 theatrical film The Rocketeer.
- In addition to his many TV guest spots prior to Lost, he had prominent recurring roles on Alias, The West Wing and JAG.
- 2005, Emmy — Outstanding Supporting Actor in a Drama Series: Nominee
- 2007, Emmy — Outstanding Supporting Actor in a Drama Series: Winner
- 2010, Emmy — Outstanding Supporting Actor in a Drama Series: Nominee
- 2005, Screen Actors Guild Awards — Outstanding Performance by an Ensemble in a Drama Series: Winner
- 1988, Independent Spirit Awards — Best Male Lead: Nominee
- Hunter O'Quinn — Son
- Lori O'Quinn — Wife
- Oliver O'Quinn — Son
- Attended University of Iowa, Iowa City, Iowa, United States; attended Central Michigan University, Mount Pleasant, Michigan, United States