Gary Cooper as Frank Flannagan

Audrey Hepburn as Ariane Chavasse / Thin Girl

Maurice Chevalier as Claude Chavasse

John McGiver as Monsieur X

Van Doude as Michel

Lise Bourdin as Madame X

Olga Valéry as Hotel Guest with Dog

Paul Bonifas as Police Chief (uncredited)

Audrey Long as Brunette (uncredited)

Charles Lemontier as General (uncredited)

Eve Marley as Tandemist (uncredited)

Moustache as Butcher (uncredited)

Jean Ozenne as Ritz Receptionist (uncredited)

Marcelle Praince as Rich Woman (uncredited)

Betty Schneider as Couple Drenched by Water Wagon (uncredited)

Alexandre Trauner as Artist (uncredited)

Audrey Young as Frank's Opera Date (uncredited)