William Gillette as Sherlock Holmes

Ernest Maupain as Professor Moriarty

Marjorie Kay as Alice Faulkner

Edward Fielding as Dr. Watson

Stewart Robbins as Benjamin Forman

Hugh Thompson as Sir Edward Leighton

Ludwig Kreiss as Baron von Stalburg

Mario Majeroni as James Larrabee

William Postance as Sidney Prince

Chester Beery as Craigin

Fred Malatesta as 'Lightfoot' McTague

Grace Reals as Madge Larrabee

Leona Ball as Therese

Burford Hampden as Billy

Marian Skinner as A Suffragette

Edward Arnold as Moriarty Henchman In Striped Cap

Frank Hamilton as Tim Leary