Tony Curtis as Nick Johnson

Rosanna Schiaffino as Francesca di Rienzi

Lionel Jeffries as Parker

Zsa Zsa Gabor as Gigi

Fenella Fielding as Fenella

Anna Quayle as Aunt Miriam

Nancy Kwan as Baby

Warren Mitchell as Conte de Rienz / Maximillian

Mischa Auer as Romeo

Noel Purcell as Capt. Daniel O'Flannery

Alan Gifford as American Brasshat

Joseph Fürst as German Brasshat

Monti DeLyle as Butler

Bernard Spear as French Inspector

Eileen Way as Italian Dressmaker

Bruno Barnabe as Head Waiter

Gábor Baraker as Gypsy Baron

Tony Baron as Baby's Boyfriend

Eunice Black as Matron

John Brandon as Radio Engineer

Windsor Davies as Radio Engineer

Franco De Rosa as Romano

John Fordyce as Boy in Orphanage

Yole Marinelli as First Maid

Miki Iveria as Second Maid

Henri Vidon as Priest

Raymond Young as Photographer

Jacqueline Bisset as Dancer

Michael Des Barres as Boy in Orphanage (uncredited)