Basil Rathbone
Sherlock Holmes
Nigel Bruce
Dr. John Watson
Dennis Hoey
Inspector Lestrade
Evelyn Ankers
Naomi Drake
Miles Mander
Giles Conover
Ian Wolfe
Amos Hodder
Charles Francis
Francis Digby, curator
Holmes Herbert
James Goodram, courier
Richard Aherne
Museum Guard Bates
Mary Gordon
Mrs. Hudson
Rondo Hatton
The Hoxton Creeper
Harry Cording
George Gelder (uncredited)
Billy Bevan
Constable With Food Tray (uncredited)
Leyland Hodgson
Customs Officer (uncredited)
Eric Wilton
Chauffeur (uncredited)
Lillian Bronson
Maj. Harker's Housekeeper (uncredited)