Timothy David Olyphant (/ˈɒlɪfənt/ OL-ih-fənt; born May 20, 1968) is an American actor. He made his acting debut at an off-Broadway theatre in 1995 in The Monogamist, won the Theatre World Award for his performance, and then originated David Sedaris' The Santaland Diaries in 1996. He then branched out to film; in the early years of his career, he was often cast in supporting villainous roles, most notably in Scream 2 (1997), Go (1999), Gone in 60 Seconds and The Broken Hearts Club (2000), A Man Apart (2003), and The Girl Next Door (2004).

He came to a broader audience through his portrayal of Sheriff Seth Bullock in HBO's western Deadwood (2004–2006), later reprising the role in Deadwood: The Movie (2019). He had starring roles in films such as Catch and Release (2006), Hitman (2007), A Perfect Getaway (2009), and The Crazies (2010), and he played the main antagonist, Thomas Gabriel, in Live Free or Die Hard (2007). Olyphant was a recurring guest star in season two of the FX legal thriller Damages (2009).