Born in Castro Valley, California on November 24, 1964, Garret Dillahunt took up journalism at the University of Washington. He later received training in acting at the New York University. He first appeared on Broadway before trying his luck in television. His first appearance was in a minor role in the daytime soap One Life to Live. It was followed by guest appearances in programs such as NYPD Blue, The X Files and Seven Days. His first film was the 1999 drama Last Call, where he starred opposite Peter Coyote and Elizabeth Rossa.
In 2001, Dillahunt appeared in the cable drama Leap Years. After guest appearances in CSI and CSI: New York, he appeared in the Western drama Deadwood, playing drunkard Jack McCall, who shot James Butler Hickok (Keith Carradine) in the head. In the program’s second season, which aired in 2005, he played another character: Francis Wolcott, the chief geologist of mining magnate George Hearst (Gerald McRaney) who is unstable and sexually violent.
In 2005, Dillahunt had played a recurring role in a story arc for the medical drama ER. His role was that of Steve Curtis, a criminal who escapes from police custody while in the emergency room. The actor also appeared in the science fiction drama The 4400, where he plays recurring character Michael Ross, a lobbyist in the Collier organization who is believed to know more about the 4400 than he has revealed. In 2007, he was cast as the inexperienced deputy sheriff Wendell in the acclaimed film No Country for Old Men, where he won a Screen Actors Guild Award with the rest of the cast for Best Cast – Motion Picture.
Dillahunt’s later credits include the drama John from Cincinnati, the 2007 film The Assassination of Jesse James by the Coward Robert Ford, and a role in Terminator: The Sarah Connor Chronicles. He has also been seen on Life, Pretty Bird, and has signed on for roles in 2008’s The Road, Water Pills, The Last House on the Left, and Burning Bright.