"A middle-aged playboy becomes fascinated by the daughter of a private detective who has been hired to entrap him with a client's wife."
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)
Jay A. Morley Jr.
Costume Design
Billy Wilder
Director
Hubert de Givenchy
Art Direction
Screenplay
William C. Mellor
Director of Photography
Christian Ferry
Location Manager
Lee Katz
Associate Producer
Chester W. Schaeffer
Editor
Ray Taylor Jr.
Assistant Director
Winifred Gibson
Script Supervisor
Albert Sendrey
Orchestrator
John G. Holden
Makeup Artist
Oliver Emert
Set Decoration
Edward Dodds
Production Manager
Paul Feyder
First Assistant Director
Noël Howard
Second Unit Director
Alain Boudet
Second Assistant Director
Lucie Lichtig
Maurice Barnathan
Set Dresser
Auguste Capelier
Assistant Art Director
Production Design
William Schorr
Doane Harrison
Del Harris
Sound Editor
Robert Tracy
Music Editor
Joseph de Bretagne
Sound Recordist
Harry L. Underwood
Camera Operator
Producer
Claude Anet
Novel
Léonide Azar
I. A. L. Diamond