Boris Karloff
Dr. Friedrich Hohner
Susanna Foster
Angela Klatt
Turhan Bey
Franz Munzer
Gale Sondergaard
Luise
Thomas Gomez
Count Seebruck
June Vincent
Marcellina
George Dolenz
Amato Roselli
Ludwig Stössel
Carl Baumann
Jane Farrar
Jarmila Vadek
Ernö Verebes
Brunn
Lotte Stein
Mama Hinzl
Scotty Beckett
The King
William Edmunds
Leon, Theatre Concierge
Jack Richardson
Musical Conductor (Uncredited)
Stuart Holmes
King's Consul (Uncredited)
Eddie Polo
Stagehand (Uncredited)
Ernie Adams
Man in Audience Next to Franz (Uncredited)
Gertrude Astor
Woman in Audience Behind Franz (Uncredited)
Grace Cunard
Backstage Maid (Uncredited)
William Desmond
Backstage Technician (Uncredited)
Francis Ford
Backstage Attendant (Uncredited)
Louis Payne
Audience Member (Uncredited)
Anne Cornwall
Audience Member (Uncredited)
Rudy Bowman
Audience Member (Uncredited)
William H. O'Brien
Audience Member (Uncredited)
Helen Gibson
Audience Member (Uncredited)
Maurice Costello
Audience Member (Uncredited)
Richard Neill
Audience Member (Uncredited)
Eric Mayne
Audience Member (Uncredited)