Grand Duchess Gloriana XII/Prime Minister Count Rupert Mountjoy/Tully Bascombe

Peter Sellers

Helen Kokintz

Jean Seberg

Will Buckley

William Hartnell

Professor Alfred Kokintz

David Kossoff

Benter

Leo McKern

Roger

Timothy Bateson

General Snippet

MacDonald Parke

United States Secretary of Defense

Austin Willis

Cobbley

Monty Landis

Pedro

Harold Kasket

Pedro

Harold Kasket

Air Raid Warden

Alan Gifford

BBC Announcer

Colin Gordon

O'Hara

George Margo

Ticket Collector (uncredited)

Jacques Cey

Mulligan

Robin Gatehouse

U.S. Policeman (uncredited)

Bill Nagy

Soviet Ambassador (uncredited)

Guy Deghy

Telephone Operator (scenes deleted)

Mavis Villiers

Spectator (uncredited)

Eve Eden

Cunard Captain

Stuart Saunders

Ken Stanley

Army Captain (uncredited)

Bill Edwards

US Policeman

Bill Nagy

Ada - Lady in Waiting (uncredited)

Mabel Etherington

Telephone Operator

Mavis Villiers

Lady in Waiting (uncredited)

Muriel Greenslade

Fenwickian (uncredited)

Fred Haggerty

British Ambassador

Charles Clay

French Ambassador

Henry de Bray

Maybury (uncredited)

Juba Kennerley

Billy Edwards

American General at the Pentagon (uncredited)

Lionel Murton

Reporter (uncredited)

Robert O'Neill

American General (uncredited)

Pat Ryan

Chester Beston

Larry Cross

Fenwickian (uncredited)

Fred Stroud

American Admiral (uncredited)

John Tatum

Air Raid Warden in Physics Lab

Wally Brown

Bird Seller (uncredited)

Fred Wood

Reporter

Robert O'Neil

Director

Jack Arnold