"The Adventure of the Speckled Band" is one of the 56 short Sherlock Holmes stories written by Scottish author Sir Arthur Conan Doyle. It is the eighth of the twelve stories collected in The Adventures of Sherlock Holmes. It is one of four Sherlock Holmes stories that can be classified as a locked room mystery. The story was first published in Strand Magazine in February 1892, with illustrations by Sidney Paget. It was published under the different title "The Spotted Band" in New York World in August 1905. Doyle later revealed that he thought this was his best Holmes story.
Doyle wrote and produced a play based on the story. It premiered at the Adelphi Theatre, London on 4 June 1910, with H. A. Saintsbury as Sherlock Holmes and Lyn Harding as Dr. Grimesby Roylott. The play, originally called The Stonor Case, differs from the story in several details, such as the names of some of the characters.