Stuart Whitman as Orvil Newton

Sarah Miles as Patricia Rawnsley

James Fox as Richard Mays

Alberto Sordi as Count Emilio Ponticelli

Robert Morley as Lord Rawnsley

Gert Fröbe as Colonel Manfred von Holstein

Jean-Pierre Cassel as Pierre Dubois

Eric Sykes as Courtney

Red Skelton as The Neanderthal Man

Terry-Thomas as Sir Percy Ware-Armitage

Flora Robson as Mother Superior

Karl Michael Vogler as Captain Rumpelstoss

Sam Wanamaker as George Gruber

Maurice Denham as Trawler Skipper

Gordon Jackson as MacDougal

John Le Mesurier as French Painter

James Robertson Justice as Narrator

Ferdy Mayne as French Official

Benny Hill as Fire Chief Perkins

Millicent Martin as Airline Hostess

Tony Hancock as Harry Popperwell

Yūjirō Ishihara as Yamamoto

Vernon Dobtcheff as Member of the French Team

Zena Marshall as Countess Sophia Ponticelli

Irina Demick as Brigitte / Ingrid / Marlene / Françoise / Yvette / Betty

Cicely Courtneidge as Colonel's Wife

Eric Barker as French Postman

Fred Emney as Colonel on Road

Davy Kaye as Jean Pascal

Jeremy Lloyd as Lieutenant Parsons

Eric Pohlmann as Italian Mayor

Marjorie Rhodes as Waitress

Norman Rossington as Assistant Fire Chief

William Rushton as Tremayne Gascoyne

Graham Stark as Fireman

Jimmy Thompson as Photographer

Michael Trubshawe as Niven

Maurice Dunster as French Policeman (uncredited)