Marcello Mastroianni
Grand Duke Nicholas Wladimirovitch Goduno
Rita Tushingham
Bridget Rafferty
Leonard Rossiter
Inspector Dudley
Bryan Pringle
Police Sergeant
Francesca Tu
Jeanne Silkingers
David Horne
Duke of Windemere
Juba Kennerley
Casino Patron (uncredited)
Ian Trigger
Popov's assistant (uncredited)
Norman Mitchell
(uncredited)
Nora Nicholson
Anastasia Petrovna