Peter Sellers
— Auguste Topaze
Nadia Gray
— Suzy
Herbert Lom
— Castel Benac
Leo McKern
— Muche
Billie Whitelaw
— Ernestine
Michael Gough
— Tamise
Joan Sims
— Colette
John Le Mesurier
— Blackmailer
John Neville
— Roger
Martita Hunt
— Baroness
Pauline Shepherd
— Lilette
Michael Sellers
— Gaston
Anne Leon
— Mrs. Tamise
Thomas Gallagher
— Policeman (uncredited)