Keith McConnell

as Sir Robert Smythe

as Sherlock Holmes

as Capt. Blake

as Harding

as Gabriel

as Rex Livingston

as Buyer

as Lord Farthingay

as Lord Lansing

as Dr. Wednesday

as Carl Reed (1 episode)

as Policeman

as Charlie

as Tom (1 episode)

as Constable Kent (archive footage) (uncredited)

as Sweeney

as James Morrison

as Reporter (1 episode)

as Usher (uncredited)

as The Fiance

as Mr. Benthall

as Chauffeur (1 episode)