Boris Karloff
Dr. Friedrich Hohner
Susanna Foster
Angela Klatt
Thomas Gomez
Count Seebruck
George Dolenz
Amato Roselli
Ludwig Stössel
Carl Baumann
William Edmunds
Leon, Theatre Concierge
Maxwell Hayes
Count Romburg
Dorothy Lawrence
Miss Metzger
Bella Lewitzky
Dancer (Uncredited)
Jack Richardson
Musical Conductor (Uncredited)
Polly Bailey
Cleaning Woman (Uncredited)
Stuart Holmes
King's Consul (Uncredited)
Eddie Polo
Stagehand (Uncredited)