| Person | Type | Job | Role(s) |
|---|---|---|---|
 Arthur Conan Doyle | Crew | Writing | Novel |
 Bernard B. Brown | Crew | Sound | Sound Director |
Bertram Millhauser | Crew | Writing | Screenplay |
Edward Curtiss | Crew | Editing | Editor |
John B. Goodman | Crew | Art | Art Direction |
John P. Fulton | Crew | Crew | Special Effects |
Martin Obzina | Crew | Art | Art Direction |
Melville Shyer | Crew | Directing | Assistant Director |
 Roy William Neill | Crew | Production | Producer, Director |
Russell A. Gausman | Crew | Art | Set Decoration |
Ted von Hemert | Crew | Art | Set Decoration |
Vera West | Crew | Costume & Make-Up | Costume Design |
 Virgil Miller | Crew | Camera | Director of Photography |
Mark Levant | Crew | Sound | Music Director |
Roswell A. Hoffmann | Crew | Camera | Camera Operator |
Alec Harford | Cast | Commissioner of the CID (uncredited) | |
 Basil Rathbone | Cast | Actor | Sherlock Holmes |
 Bess Flowers | Cast | Actress | Bar Patron (seen in mirror) (uncredited) |
 Boyd Irwin | Cast | Actor | Short-Tempered Officer Closing Window (uncredited) |
 Coulter Irwin | Cast | Actor | Corporal Williams |
 Eric Mayne | Cast | Actor | Member of Mesmer Club (uncredited) |
 Eve Amber | Cast | Actress | Maude Fenwick |
 Frederick Worlock | Cast | Actor | Dr. Onslow |
 Henry Daniell | Cast | Actor | Professor James Moriarty |
 Hillary Brooke | Cast | Actress | Lydia Marlowe |
John Burton | Cast | Actor | Waring the Mesmerist (uncredited) |
 Kay Harding | Cast | Actress | 4th Victim (uncredited) |
 Mary Gordon | Cast | Actress | Mrs. Hudson |
 Matthew Boulton | Cast | Actor | Inspector Gregson |
 Nigel Bruce | Cast | Actor | Dr. John Watson |
 Olaf Hytten | Cast | Actor | Fenwick's Butler Norris (uncredited) |
 Paul Cavanagh | Cast | Actor | Sir George Fenwick |
Percival Vivian | Cast | Dr. Simnell | |
 Sally Shepherd | Cast | Actress | Crandon |
Tony Ellis | Cast | Actor | Carter the Hypnotized Subject (uncredited) |
 William H. O'Brien | Cast | Actor | Pembrook House Waiter (uncredited) |
Harold De Becker | Cast | Shoelace Vendor Henchman (uncredited) | |
| Person | Type | Job | Role(s) |
