Harry Arthur Saintsbury, usually called H. A. Saintsbury (18 December 1869 – 19 June 1939) was an English actor and playwright. A leading man, he became well known for his stage interpretation of Sherlock Holmes, was an early mentor of Charlie Chaplin and is considered an authority on the work of Sir Henry Irving.

Called Arthur by his friends, professionally he used his initials. Most of his plays appeared under the nom-de-plume of Jay Nibb.