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