Grand Duchess Gloriana XII / Prime Minister Count Rupert Mountjoy / Tully Bascombe
Peter Sellers
Helen Kokintz
Jean Seberg
BBC Announcer
Colin Gordon
Pedro
Harold Kasket
Soviet Ambassador (uncredited)
Guy Deghy
Spectator (uncredited)
Eve Eden
Army Captain (uncredited)
Bill Edwards
Ada - Lady in Waiting (uncredited)
Mabel Etherington
Lady in Waiting (uncredited)
Muriel Greenslade
Fenwickian (uncredited)
Fred Haggerty
Maybury (uncredited)
Juba Kennerley
O'Hara (uncredited)
George Margo
Will Buckley
William Hartnell
American General at the Pentagon (uncredited)
Lionel Murton
U.S. Policeman (uncredited)
Bill Nagy
Reporter (uncredited)
Robert O'Neil
American General (uncredited)
Pat Ryan
Sergeant (uncredited)
Stuart Saunders
Fred Stroud
American Admiral (uncredited)
John Tatum
Telephone Operator (uncredited)
Mavis Villiers
Bird Seller (uncredited)
Fred Wood
Professor Alfred Kokintz
David Kossoff
Benter
Leo McKern
General Snippet
MacDonald Parke
United States Secretary of Defense
Austin Willis
Roger
Timothy Bateson
Cobbley
Monte Landis
Air Raid Warden
Alan Gifford
Director
Jack Arnold
Screenplay
Stanley Mann
Roger MacDougall
Novel
Leonard Wibberley
Producer
Walter Shenson
Original Music Composer
Edwin Astley
Director of Photography
John Wilcox
Editor
Raymond Poulton
Mechanical Designer
Gerald Endler
Associate Producer
Jon Penington
Production Supervisor
Leon Becker
Art Direction
Geoffrey Drake
Production Manager
James H. Ware
Title Designer
Maurice Binder
Camera Operator
Austin Dempster
Sound
Red Law
George Stephenson
Assistant Director
Philip Shipway
Continuity
Pamela Davies
Sound Editor
Richard Marden
Makeup Artist
Stuart Freeborn
Second Unit Cinematographer
John Winbolt
Costume Designer
Anthony Mendleson
Hairdresser
Joyce James
Conductor