Hour of the Gun is a 1967 Western film depicting Wyatt Earp and Doc Holliday during their 1881 battles against Ike Clanton and his brothers in the Gunfight at the O.K. Corral, and the gunfight's aftermath in and around Tombstone, Arizona, starring James Garner as Earp, Jason Robards as Holliday, and Robert Ryan as Clanton. The film was directed by John Sturges.

John Henry Holliday, better known as Doc Holliday, was a dentist and later a gambler, gunfighter, and a close friend and associate of lawman Wyatt Earp. Holliday is best known for his role in the events surrounding and his participation in the Gunfight at the O.K. Corral in Tombstone, Arizona. He developed a reputation as having killed more than a dozen men in various altercations, but modern researchers have concluded that, contrary to popular myth-making, Holliday killed only one to three men. Holliday's colorful life and character have been depicted in many books and portrayed by well-known actors in numerous movies and television series.