Stewart Granger (Rudolf Rassendyll/King Rudolf V)
Deborah Kerr (Princess Flavia)
James Mason (Rupert of Hentzau)
Louis Calhern (Col. Zapt)
Jane Greer (Antoinette de Mauban)
Lewis Stone (The Cardinal)
Peter J. Votrian (Newsboy)
Michael Vallon (Assistant Passport Official)
Elizabeth Slifer (Woman)
Victor Romito (Aide)
Steve Roberts (Lauengram)
Charles Watts (Porter)
Bud Wolfe (Bersonin)
Stanley Logan (British Ambassador)
John W. Goldsworthy (Archbishop)
Manuel Paris (Nobleman)
George Slocum (Sandwich Vendor)
Bruce Payne (Court Chamberlain)
Gordon Richards (Dignitary)
Hugh Prosser (Uhlan Guard)
Alex Pope (Husband)
Eric Alden (Krafstein)
Guy Bellis (Lord Chamberlain)
Mary Carroll (German Wife)
Frank Elliott
Kathleen Freeman (Gertrude)
Thomas Brown Henry (Detchard)
George Lewis
Doris Lloyd (Ambassador's Wife)
Forbes Murray (Nobleman with Cardinal)
Joseph Mell (R.R. Guard)
Jay Adler (Customs officer (uncredited))
Alphonse Martell
Paul Marion (Guard)
Peter Mamakos (De Gautet)
Robert Douglas (Michael, Duke of Strelsau)
Robert Coote (Fritz von Tarlenheim)
Peter Brocco (Johann)
Francis Pierlot (Josef)