'The Adventure of the Musgrave Ritual' is a Sherlock Holmes story by Arthur Conan Doyle, first published in The Strand Magazine (UK) and Harper's Weekly (US) in May 1893. It's collected in The Memoirs of Sherlock Holmes.

Unlike most stories narrated by Dr. Watson, this one is told mainly by Holmes himself, with Watson providing the introduction. It's one of Holmes's earliest cases, showcasing his deductive skills. The story has similarities to Edgar Allan Poe's works like The Gold-Bug and The Cask of Amontillado.

Here, Holmes reviews old records and recounts the case of Reginald Musgrave, an old university acquaintance, who seeks help after strange events at his family estate, Hurlstone. The Musgraves have a centuries-old ritual where each eldest son must memorize and recite a mysterious poem upon coming of age.