He has appeared in more than 30 films including The Beat Generation in 1959; The Victors in 1963; as a surfer named Eskimo in Ride the Wild Surf in 1964; In Harm’s Way (1965) with John Wayne, Kirk Douglas, and Henry Fonda; Ambush Bay (1966); The Invincible Six (1970); Two-Lane Blacktop (1971); and The Last Movie (1971).

In 1975, he starred in the movie Moonrunners, where he played the character Grady Hagg in the influence for the television series The Dukes of Hazzard. He was also in Zebra Force and Trackdown co-starring Karen Lamm and Erik Estrada in 1976; The Ransom (a k a Assault on Paradise) (1977); Blackout (1978); Monstroid (1980); Crazy Jungle Adventure [de] (1982); Code Name Zebra (1987); Hollywood Cop (1987); Jake Spanner, Private Eye (1989); and Fatal Mission (1990).

Mitchum was born in Los Angeles, California, the eldest son of actor Robert Mitchum and his wife, Dorothy Spence. His brother is actor Christopher Mitchum, and he is the uncle of actor Bentley Mitchum. His only child was born during his marriage to Wende Wagner, an actress who died in 1997, of cancer.