
Margaret Rutherford
Grand Duchess Gloriana XIII
Acting

Ron Moody
Prime Minister Rupert Mountjoy
Acting

Bernard Cribbins
Vincent Mountjoy
Acting

David Kossoff
Professor Kokintz
Acting

Terry-Thomas
Maurice Spender
Acting

June Ritchie
Cynthia
Acting

John Le Mesurier
British Delegate
Acting

John Phillips
Bracewell - U.S. Delegate
Acting

Eric Barker
M.I.5. Man
Acting

Roddy McMillan
Benter
Acting

Tom Aldredge
Wendover
Acting

Michael Trubshawe
British Aide
Acting

Peter Sallis
Russian Delegate
Acting

Clive Dunn
Bandleader
Acting

Graham Stark
Standard Bearer
Acting

Mario Fabrizi
Mario - the Valet
Acting
![Jan Conrad]()
Jan Conrad
Russian Aide
Acting

John Bluthal
Von Neidel (as John Bluthall)
Acting

Archie Duncan
U.S.A.F. General
Acting

Guy Deghy
Russian Scientist
Acting

Richard Marner
Russian Air Force General
Acting

Allan Cuthbertson
Member of Whitehall Conference
Acting

Robin Bailey
Member of Whitehall Conference
Acting
![Gerald Andersen]()
Gerald Andersen
Member of Whitehall Conference
Acting
![Gordon Phillott]()
Gordon Phillott
Civil Sergeant
Acting

John Wood
Countryman
Acting
![George Chisholm]()
George Chisholm
Wine Waiter
Acting
![Rosemary Scott]()
Rosemary Scott
Launching Lady
Acting
![Frank Duncan]()
Frank Duncan
News Announcer
Acting

Ed Bishop
American Astronaut (as Edward Bishop)
Acting

Bill Edwards
American Astronaut
Acting

Laurence Herder
Russian Astronaut
Acting

Harvey Hall
Russian Astronaut
Acting
![Beverly Bennett]()
Beverly Bennett
(Uncredited)
Acting
![Paul Beradi]()
Paul Beradi
Ukraine Delegate (Uncredited)
Acting
![Ernest Blyth]()
Ernest Blyth
Dignatory at Ship Launching (Uncredited)
Acting
![Michael Caspi]()
Michael Caspi
(Uncredited)
Acting
![Paul Cole]()
Paul Cole
(Uncredited)
Acting
![Douglas Cooper]()
Douglas Cooper
Fenwickian (Uncredited)
Acting

Larry Cross
(Uncredited)
Acting
![Victor Croxford]()
Victor Croxford
Valet (Uncredited)
Acting
![George Curtis]()
George Curtis
Councillor (Uncredited)
Acting

Stringer Davis
1st Councillor (Uncredited)
Acting

Charles Dyer
Bit Part (Uncredited)
Writing

Lucy Griffiths
Lady-in-Waiting (Uncredited)
Acting
![Sandra Hampton]()
Sandra Hampton
April (Uncredited)
Acting
![Robert Haynes]()
Robert Haynes
(Uncredited)
Acting
![Murray Kash]()
Murray Kash
(Uncredited)
Acting
![Frederick Kelsey]()
Frederick Kelsey
Fenwickian (Uncredited)
Acting

Bruce Lacey
Bandleader (Uncredited)
Acting
![Anthony Lang]()
Anthony Lang
Councillor (Uncredited)
Acting
![Frank Lieberman]()
Frank Lieberman
American Civilian (Uncredited)
Acting
![Martin Lyder]()
Martin Lyder
Fenwickian (Uncredited)
Acting
![Jack Mandeville]()
Jack Mandeville
Representative at United Nations (Uncredited)
Acting
![Coral Morphew]()
Coral Morphew
Peasant Girl (Uncredited)
Acting
![Carolyn Pertwee]()
Carolyn Pertwee
June (Uncredited)
Acting
![Stuart Saunders]()
Stuart Saunders
Sergeant (Uncredited)
Acting

Kevin Scott
American Journalist (Uncredited)
Acting
![George Spence]()
George Spence
Man in Market (Uncredited)
Acting
![Reg Thomason]()
Reg Thomason
Opposition MP (Uncredited)
Acting
![Fred Wood]()
Fred Wood
Bird Seller (Uncredited)
Acting