David Knight
— Ted Hutchens
Odile Versois
— Anna Szobek
Theodore Bikel
— Joseph
David Kossoff
— Geza Szobek
Joseph Tomelty
— Moffatt
Paul Carpenter
— Gregg Pearson
Peter Illing
— Dr. Weissbrod
John McLaren
— Col. Margetson
Bernard Rebel
— Stefan
Jill Adams
— Judy (uncredited)
Robin Bailey
— Thomas Cook cashier (uncredited)
Dora Bryan
— Switchboard Operator (uncredited)
Peter Dyneley
— Regan (uncredited)
Dwight D. Eisenhower
— Himself, in photo (uncredited)
Percy Herbert
— Richards (uncredited)
Sam Kydd
— Driver, Embassy car JAK711 (uncredited)
Victor Maddern
— Sailor (uncredited)
Betty Marsden
— Mrs. Forrester (uncredited)
Aubrey Mather
— Waiter (uncredited)
Joan Sims
— Telephone Operator, American Embassy (uncredited)
Russell Waters
— Counterman (uncredited)