Basil Rathbone

Sherlock Holmes

Nigel Bruce

Dr. John Watson

Hillary Brooke

Lydia Marlowe

Henry Daniell

Professor James Moriarty

Paul Cavanagh

Sir George Fenwick

Matthew Boulton

Inspector Gregson

Eve Amber

Maude Fenwick

Frederick Worlock

Dr. Onslow

Percival Vivian

Dr. Simnell

Coulter Irwin

Corporal Williams

Sally Shepherd

Crandon

Mary Gordon

Mrs. Hudson

John Burton

Waring the Mesmerist (uncredited)

Harold De Becker

Shoelace Vendor Henchman (uncredited)

Tony Ellis

Carter the Hypnotized Subject (uncredited)

Bess Flowers

Bar Patron (seen in mirror) (uncredited)

Kay Harding

4th Victim (uncredited)

Alec Harford

Commissioner of the CID (uncredited)

Olaf Hytten

Fenwick's Butler Norris (uncredited)

Boyd Irwin

Short-Tempered Officer Closing Window (uncredited)

Eric Mayne

Member of Mesmer Club (uncredited)

William H. O'Brien

Pembrook House Waiter (uncredited)