John Wayne as McQ

Eddie Albert as Kosterman

Diana Muldaur as Lois

Colleen Dewhurst as Myra

Clu Gulager as Toms

David Huddleston as Pinky

Julian Christopher as J.C.

Al Lettieri as Santiago

Julie Adams as Elaine

Roger E. Mosley as Rosey

William Bryant as Stan Boyle

Richard Kelton as Radical

Joe Tornatore as LaSalle

Dick Friel as Bob Mahoney

Richard Eastham as Walter Forrester

Fred Waugh as Bodyguard

Larry Buck as Chief Grogan (uncredited)

Leslie Carlson as Radical (uncredited)

Robert Dietrich as 1st Heistman (uncredited)

Matt Donovick as 2nd Heistman (uncredited)

Jack Evans as Harry (uncredited)

June Foray as Disk Jockey (voice) (uncredited)

Azizi Johari as Hot Dog Girl at Snack Bar (uncredited)

James Johnson as 1st Patrol Car Officer (uncredited)

Gary Lynn as 1st Patrol Car Officer (uncredited)

Arthur Mason as Sal (uncredited)

Steve McDonald as Police Officer (uncredited)

Cynthia Mitchell as 2nd Fox (uncredited)

Steve Moriarty as Hospital Orderly / Driver (uncredited)

Hal Needham as Santiago Henchman (uncredited)

John Price as Punk Kid (uncredited)

Eugene Rice as Workman (uncredited)

Chuck Roberson as Santiago's Bodyguard (uncredited)

Marvin Rosand as Property Officer (uncredited)

Kim Sanford as Ginger McQ (uncredited)

George Selvidge as Commissioner (uncredited)

Steve Singer as Emergency Doctor (uncredited)

Glenn R. Wilder as Motorcyclist (uncredited)