Directed by Jack Arnold
Produced by Carl Foreman, Jon Penington, Walter Shenson
Based on Novel by Leonard Wibberley
Screenplay by Roger MacDougall, Stanley Mann
Cinematography by John Wilcox
Film Editing by Raymond Poulton
Music by Edwin T. Astley
Art Direction by Geoffrey Drake
Costume Design by Anthony Mendleson
Mechanical Effects : Gerald Endler
Cast
Peter Sellers (Grand Duchess Gloriana XII/Prime Minister Count Rupert Mountjoy/Tully Bascombe)
Jean Seberg (Helen Kokintz)
William Hartnell (Will Buckley)
David Kossoff (Professor Alfred Kokintz)
Leo McKern (Benter)
MacDonald Parke (General Snippet)
Austin Willis (United States Secretary of Defense)
Timothy Bateson (Roger)
Monty Landis (Cobbley)
Alan Gifford
Colin Gordon (BBC Announcer)
Harold Kasket (Pedro)
Robert O'Neill (Reporter)
Mavis Villiers (Telephone Operator)
Jacques Cey (Ticket Collector)
Charles Clay (British Ambassador)
Harry De Bray (French Ambassador)
Guy Deghy (Soviet Ambassador)
Bill Edwards (Army Captain)
Richard Gatehouse (Mulligan)
George Margo (O'Hara)
Bill Nagy (U.S. Policeman)
Stuart Saunders (Cunard Captain)
Ken Stanley (Cunard Second Officer)