Cary Grant as Peter Joshua

Audrey Hepburn as Regina Lampert

Walter Matthau as Hamilton Bartholemew

James Coburn as Tex Panthollow

George Kennedy as Herman Scobie

Dominique Minot as Sylvie Gaudel

Ned Glass as Leopold Gideon

Jacques Marin as Edouard Grandpierre

Paul Bonifas as Mr. Felix

Thomas Chelimsky as Jean-Louis Gaudel

Marc Arian as Subway Passenger (uncredited)

Claudine Berg as Maid (uncredited)

Marcel Bernier as Taxi Driver (uncredited)

Albert Daumergue as Man in Stamp Market (uncredited)

Raoul Delfosse as Taxi Driver (uncredited)

Stanley Donen as Man in Elevator (voice) (uncredited)

Jean Gold as Writer On Cafe Terrace (uncredited)

Chantal Goya as (uncredited)

Clément Harari as German Tourist (uncredited)

Monte Landis as Master of Ceremonies at Club (uncredited)

Bernard Musson as Hotel Receptionnist (uncredited)

Antonio Passalia as Italian Representative at URESCO (uncredited)

Jacques Préboist as Ice Cream Salesman (uncredited)

Peter Stone as Man in Elevator / Marine (voice) (uncredited)

Michel Thomass as Embassy Driver (uncredited)

Roger Trapp as Mortuary Employee (uncredited)

Louis Viret as Hallmark Employee On Subway (uncredited)