Warner Oland
Charlie Chan
Boris Karloff
Gravelle
Keye Luke
Lee Chan
William Demarest
Sergeant Kelly
Guy Usher
Inspector Regan
Margaret Irving
Mme. Lilli Rochelle
Gregory Gaye
Enrico Borelli
Nedda Harrigan
Mme. Lucretia Borelli
Frank Conroy
Mr. Whitely
Charlotte Henry
Mlle. Kitty
Thomas Beck
Phil Childers
Maurice Cass
Mr. Arnold
Tom McGuire
Pop Morris - Stage Doorman
Marc Lawrence
Undetermined Minor Role (uncredited) (unconfirmed)
Joan Woodbury
Dancer in Opera (uncredited)
William Bailey
Detective (uncredited)
Charles Bancroft
Soldier in Opera (uncredited)
John Bleifer
Murdered Orderly (uncredited)
Stanley Blystone
Backstage Cop Who Shoots Gravelle (uncredited)
Myrta Bonillas
Villager in Opera (uncredited)
Raymond Brown
Guard (uncredited)
Carita Crawford
Dancer in Opera (uncredited)
Patrick Cunning
Villager in Opera (uncredited)
Zari Elmassian
Mme. Rochelle (singing voice) (uncredited)
Frank Fanning
Cop (uncredited)
Jim Farley
Detective (uncredited)
Adolph Faylauer
Opera Spectator (uncredited)
Larry Fisher
Cop (uncredited)
Benson Fong
Opera Supernumerary (uncredited)
J. C. Fowler
Opera Spectator (uncredited)
Otto Fries
Innkeeper (uncredited)
Bud Geary
Cop (uncredited)
Milton Gowman
Villager in Opera (uncredited)
Herschel Graham
Villager in Opera (uncredited)
Harrison Greene
Detective (uncredited)
Julia Griffith
Opera Spectator (uncredited)