Marcello Mastroianni
Grand Duke Nicholas Wladimirovitch Goduno
                                    Rita Tushingham
Bridget Rafferty
                                    Elaine Taylor
Victoria
                                    Margaret Blye
Honey
                                    Warren Mitchell
Popov
                                    Leonard Rossiter
Inspector Dudley
                                    Bill Fraser
Bookseller
                                    Bryan Pringle
Police Sergeant
                                    Francesca Tu
Jeanne Silkingers
                                    David Horne
Duke of Windemere
                                    Charles Lloyd Pack
Butler
                                    Anne Blake
Nashka
Juba Kennerley
Casino Patron (uncredited)
                                    Ian Trigger
Popov's assistant (uncredited)
                                    Norman Mitchell
(uncredited)
                                    Nora Nicholson
Anastasia Petrovna
                                    Rosalind Knight
Museum Visitor in Pink Dress (uncredited)
Diamonds for Breakfast
Released