John Wayne
Col. Cord McNally
Jorge Rivero
Capt. Pierre Cordona
Jennifer O'Neill
Shasta Delaney
Jack Elam
Phillips
Christopher Mitchum
Sgt. Tuscarora Phillips
Victor French
Ketcham
Susana Dosamantes
Maria Carmen
Sherry Lansing
Amelita
David Huddleston
Dr. Ivor Jones
Mike Henry
Rio Lobo Sheriff 'Blue Tom' Hendricks
Bill Williams
Blackthorne Sheriff Pat Cronin
Jim Davis
Riley
Dean Smith
Bide
Robert Donner
Whitey Carter
George Plimpton
George, Whitey's 4th Henchman
Edward Faulkner
Lt. Harris
Peter Jason
Lt. Ned Forsythe
Chuck Courtney
Chuck, Whitey's 2nd Henchman
Robert Rothwell
Whitey's 3rd Henchman
Don 'Red' Barry
Feeny - Bartender (uncredited)
Sondra Currie
Blackthorne Prostitute (uncredited)
Chuck Hayward
(uncredited)
Conrad Hool
Bart (uncredited)
Lance Hool
Picket (uncredited)
John Hudkins
Rio Lobo Deputy (uncredited)
Michael Jeffers
Barfly in Blackthorne (uncredited)
Frank Kennedy
Minor Role (uncredited)
Richard LaMarr
Man in Army Post Saloon (uncredited)
John McKee
Rio Lobo Deputy (uncredited)
Boyd 'Red' Morgan
Train Engineer (uncredited)
William H. O'Brien
Man in Army Post Saloon (uncredited)
Gregg Palmer
Pete - Henchman (uncredited)
Jim Prejean
Union Soldier (uncredited)
Rudy Robbins
Man (uncredited)
Chuck Roberson
Corporal in Baggage Car (uncredited)
Danny Sands
Man Delivering Message to Jail (uncredited)
Cap Somers
Card Player (uncredited)
Bob Steele
Rio Lobo Deputy (uncredited)
Tommy Tedesco
Guitar Player in Opening Credits (uncredited)
Ethan Wayne
Boy (uncredited)
Hank Worden
Hank - Hotel Clerk (uncredited)