Basil Rathbone character Sherlock Holmes
Nigel Bruce character Dr. Watson
Ida Lupino character Ann Brandon
Alan Marshal character Jerrold Hunter
Terry Kilburn character Billy
George Zucco character Professor Moriarty
Henry Stephenson character Sir Ronald Ramsgate
E.E. Clive character Inspector Bristol
Arthur Hohl character Henchman Bassick
May Beatty character Mrs. Jameson, Brandon Housekeeper
Peter Willes character Lloyd Brandon
Frank Dawson character Dawes, Moriarty's servant
Mary Gordon character Mrs. Hudson
Holmes Herbert character Justice of the Court
George Regas character Henchman Mateo
Anthony Kemble-Cooper character Tony Conyngham (as Anthony Kemble Cooper)
Mary Forbes character Lady Conyngham
Leonard Mudie character Barrows - Moriarty's Attorney (uncredited)
Robert Nobel character Foreman of the Jury (uncredited)
Ivan F. Simpson character Gates - Trial Prosecutor (uncredited)
Neil Fitzgerald character Clerk of the Court (uncredited)
Frank Baker character Tompkins (uncredited)
Denis Greene character Denis Green (uncredited)
Robert Cory character Tower Sentry (uncredited)
Gordon Hart character Guard (uncredited)
Keith Hitchcock character Constable (uncredited)
Ivo Henderson character Bobby (uncredited)
Leyland Hodgson character Bobby (uncredited)
Boyd Irwin character Bobby (uncredited)
Charles Irwin character Marine Sergeant (uncredited)
Robert R. Stephenson character Cabby (uncredited)
Harry Cording character Second Fake Constable (uncredited)
Eric Wilton character Conyngham Butler (uncredited)
William Austin character Inquisitive Stranger
Frank Benson character Cockney (uncredited)
Ted Billings character Pub Customer (uncredited)