John Porter
Elsworth Toohey
Marchese Alessandro de Granazia
Sir Hugh De Bracy
Duque de Lorca
Michael, Duke of Strelsau
General
Agamemnon
Sir Christopher Hatton
Uncle Morton Stearnes
Jones
Sir Alex Gordon (uncredited)
Dr. Michaels
Philip Cagle
Alexander Narbonne
Briefing Officer
Lt. Michael Landers
Sir Giles Amaury
Dr. Edward Jeffreys
John Flight
John Tyson
Benton
Ken Blake
Kit Woods
Commander von Molter
Gen. Benedict Arnold
Edward Whymper
Nigel Taplow
Richard Marquess
Col. von Broeck
Col. James Parker
Colonel Creighton
Saint Ebenezer / Pulo Besar
Aubrey Milburn
Danzer
Narrator (voice) (uncredited)
Stanley Baldwin
Lord Breethorpe
Capt. Markham
Allen Bardeman
Godfrey Marvin
Stephen Paradou
Self
Dick Summers
Inspector Charles Tarrant
Antony Hugh Swinburne
Frank Hunter
Harrison Ackroyd
Albert Othery
Roger Howard
Gen. George Washington
Paul McCord
Inspector Ben Liebenberg
Frank Pierce
Gen. Cornwallis
Dr. Theophilus