Steve McQueen
Henri "Papillon" Charriere
George Coulouris
Dr. Chatal
William Smithers
Warden Barrot
Barbara Morrison
Mother Superior
Don Hanmer
Butterfly Trader
Richard Angarola
Commandant
Jack Denbo
Classification Officer
Anne Byrne Hoffman
Mrs. Dega (uncredited)
Dalton Trumbo
Commandant (uncredited)
Richard Farnsworth
Manhunter (uncredited)
Peter Brocco
Doctor (uncredited)