Dudley Moore as Doctor Watson / Mr. Spiggot / Mrs. Ada Holmes / Piano Player

Peter Cook as Sherlock Holmes

Denholm Elliott as Stapleton

Joan Greenwood as Beryl Stapleton

Hugh Griffith as Frankland

Irene Handl as Mrs. Barrymore

Terry-Thomas as Dr. Mortimer

Max Wall as Arthur Barrymore

Kenneth Williams as Sir Henry Baskerville

Roy Kinnear as Selden the Axe Murderer

Dana Gillespie as Mary Frankland

Lucy Griffiths as Iris

Prunella Scales as Glynis

Ava Cadell as Marsha

Jessie Matthews as Mrs. Tinsdale

Spike Milligan as Policeman

Penelope Keith as Massage Receptionist

Anna Wing as Sausage and Mash Lady

Vivien Neves as Nun

Josephine Tewson as Nun

Rita Webb as Elder Masseuse

Henry Woolf as Shopkeeper

Jacquie Stevens as Nun