Alain Delon
Role: Mr. Robert Klein
Jeanne Moreau
Role: Florence
Francine Bergé
Role: Nicole
Juliet Berto
Role: Jeanine, Robert's mistress
Jean Bouise
Role: Seller of the painting
Suzanne Flon
Role: Concierge of rue des Abbesses
Massimo Girotti
Role: Charles, Florence's husband
Michael Lonsdale
Role: Pierre
Michel Aumont
Role: Jew Affairs Section Official
Roland Bertin
Role: Newspaper Director
Jean Champion
Role: Morgue keeper
Etienne Chicot
Role: Policeman
Gérard Jugnot
Role: Photographer
Hermine Karagheuz
Role: Young Worker
Jacques Maury
Role: Professor Montandon
Fred Personne
Role: Police Commissioner
Francine Racette
Role: Françoise / Cathy / Isabelle
Isabelle Sadoyan
Role: Examined Woman
Louis Seigner
Role: Mr. Klein's Father
Lucienne Le Marchand
Role:
Pierre Vernier
Role: Policeman
Joseph Losey
Role: Man at the Vel d'Hiv (uncredited)
Brigitte Ariel
Role: (uncredited)
Marius Balbinot
Role: (uncredited)
Maurice Baquet
Role: Musician (uncredited)
Philippe Brizard
Role: (uncredited)
Jenny Clève
Role: (uncredited)
Raymond Danon
Role: (uncredited)
Christian de Tillière
Role: Auctioneer (uncredited)
Michel Delahaye
Role: (uncredited)
Bernard-Pierre Donnadieu
Role: Extra (uncredited)
Pierre Frag
Role: Georges, Newspaper Seller (uncredited)
Mireille Franchino
Role: (uncredited)
David Gabison
Role: Bellboy (uncredited)
Maurice Jany
Role: Driver in Ivry-la-Bataille (uncredited)
Stephane Quatrehomme
Role: Pierre's Son (uncredited)
Jean Topart
Role: Speaker's voice (voice) (uncredited)
Danielle Verne
Role: Deportee (uncredited)
Thierry de Brem
Role: (uncredited)
Tina Aumont
Role: Spectator (uncredited)
Nathalie Rigaux
Role: Little girl at the Vel d'Hiv (uncredited)