Peter Lorre
Professor Karl Fenninger
Boris Karloff
Judge Spencer Mainwaring
Bela Lugosi
Prince Saliano
Helen Parrish
Janis Bellacrest
Dennis O'Keefe
Chuck Deems
Alma Kruger
Aunt Margo Bellacrest
Mary Bovard
Mary (uncredited)
Jeff Corey
Mr. Corey (uncredited)
Louise Currie
Marion (uncredited)
Bess Flowers
Lady In Taxi (uncredited)
Jeanne Houser
Jean (uncredited)
Richard Kipling
Script Man (uncredited)
Eleanor Lawson
Ms. Gaby Lawson (uncredited)
Larry McGrath
Apartment Complainer (uncredited)
Frank Mills
Cabbie (uncredited)
Mimi Montaye
Mimi (uncredited)
Dorothy Moore
Penny (uncredited)
Leonard Mudie
Real Karl Fenninger (uncredited)
Joseph North
Servant (uncredited)
Frank O'Connor
Apartment Responder (uncredited)
Beulah Parkington
Mother (uncredited)
Jane Patten
Jane (uncredited)
Eugenia Rafee
French Maid (uncredited)
William Telaak
Mac (uncredited)
Joan Warner
Joan (uncredited)
Guy Webster
Infant (uncredited)
Mary Martha Wood
Georgia (uncredited)