Sherlock Holmes is a four-act play by William Gillette and Sir Arthur Conan Doyle, based on Conan Doyle's character Sherlock Holmes. After three previews it premiered on Broadway November 6, 1899, at the Garrick Theatre in New York City.

Recognizing the success of his character Sherlock Holmes, Conan Doyle decided to pen a play based on him.

American theatrical producer Charles Frohman approached Conan Doyle and requested the rights to Holmes. While nothing came of their association at that time, it did inspire Conan Doyle to pen a five-act play featuring Holmes and Professor Moriarty. Upon reading the play, Frohman felt that it was unfit for production and instead persuaded Conan Doyle that actor William Gillette would be an ideal Holmes and would also be the perfect person to rewrite the play. Gillette, a successful playwright, donned a deerstalker and cape to visit Conan Doyle and request permission not only to perform the part but to rewrite it himself.

The play itself drew material from Conan Doyle's published stories "A Scandal in Bohemia", "The Final Problem" and A Study in Scarlet, while adding much that was new as well. As the plot was largely taken from Doyle's canon, with some dialogue directly lifted from his original stories, Doyle was credited as a co-author, even though Gillette wrote the play.

Gillette took great liberties with the character, such as giving Holmes a love interest. While Conan Doyle was initially uncomfortable with these additions, the success of the play softened his views; he said, "I was charmed both with the play, the acting, and the pecuniary result." Doyle later recounted how he had received a cable from Gillette inquiring, "May I marry Holmes?", to which Conan Doyle replied, "You may marry him, murder him, or do anything you like to him." The love interest was modelled on Irene Adler's role in "A Scandal in Bohemia", with Gillette reinventing the character and renaming her "Alice Faulkner".

Gillette's play features Professor Moriarty as the villain, but Gillette names him "Robert Moriarty". At this point no forename had been given for Moriarty in Conan Doyle's stories.

Conan Doyle had mentioned an unnamed pageboy in "A Case of Identity", and Gillette utilized the character and christened him "Billy". Conan Doyle himself would later reintroduce the character into some Holmes stories and continue using the name Billy.

The text of the play was revised numerous times during its long series of runs. The original text of 1899 was revised with corrections in 1901. There was a further "corrected and expurgated text" of approximately 1923, and a final revision for the "farewell revival" of 1929–1930. When the play was published in book form (as opposed to a play script) by Doubleday, Doran & Company in 1935, further corrections were made, as described by Vincent Starrett in his introduction: