In 1958, Mitchum was cast in two episodes of the crime drama Richard Diamond, Private Detective, starring David Janssen. He played Joe in the episode “Short Haul” and Jimmy Logan in “Bungalow Murder”.

On September 15, 1959, Mitchum appeared in the premiere episode “Stage Stop” of the Western series Laramie.

Mitchum was cast in 1960 as Pickalong in 10 episodes of the Western series Riverboat, starring Darren McGavin. The same year, he appeared in the Western series The Rebel, starring Nick Adams. He also appeared as Hal Swanson in the 1960 episode “Silver Killers” of the Western series Tombstone Territory.

From 1965 to 1967, Mitchum had the recurring role of Trooper Hoffenmueller in 11 episodes of the sitcom F Troop, starring Forrest Tucker, Larry Storch, and Ken Berry. In the 1967 episode of Batman “Surf’s Up! Joker’s Under!”, he guest-starred as the character Hot Dog Harrigan.

Mitchum was a writer, poet, singer, and guitar player. An autobiography/biography about his life and career and that of his brother Robert was published in 1998, called Them Ornery Mitchum Boys. He composed the piece “America, Why I Love Her”, which John Wayne included in his book and album of the same name. The piece and a short film with Wayne’s narration were aired at many television stations at sign-off time before stations began broadcasting 24 hours a day in the late 1970s and early 1980s. Wayne is often mistakenly credited with composing the piece.

Mitchum died on November 29, 2001, after complications of three strokes. He was 82.