Treasure Island is an adventure novel by Scottish author Robert Louis Stevenson, narrating a tale of "buccaneers and buried gold". Its influence is enormous on popular perceptions of pirates, including such elements as treasure maps marked with an "X", schooners, the Black Spot, tropical islands, and one-legged seamen bearing parrots on their shoulders.

Treasure Island is traditionally considered a coming-of-age story and is noted for its atmosphere, characters, and action. It is one of the most frequently dramatized of all novels. It was originally serialized in the children's magazine Young Folks between 1881 through 1882 under the title Treasure Island, or the mutiny of the Hispaniola, credited to the pseudonym "Captain George North". It was first published as a book on 14 November 1883, by Cassell & Co.

Stevenson conceived the idea of Treasure Island (originally titled, "The Sea Cook: A Story for Boys") from a map of an imaginary, romantic island idly drawn by Stevenson and his stepson Lloyd Osbourne on a rainy day in Braemar, Scotland. Stevenson had just returned from his first stay in America, with memories of poverty, illness, and adventure (including his recent marriage), and a warm reconciliation between his parents had been established. Stevenson himself said in designing the idea of the story that, "It was to be a story for boys; no need of psychology or fine writing; and I had a boy at hand to be a touchstone. Women were excluded... and then I had an idea for Long John Silver from which I promised myself funds of entertainment; to take an admired friend of mine... to deprive him of all his finer qualities and higher graces of temperament, and to leave him with nothing but his strength, his courage, his quickness, and his magnificent geniality, and to try to express these in terms of the culture of a raw tarpaulin." Completing 15 chapters in as many days, Stevenson was interrupted by illness and, after leaving Scotland, continued working on the first draft outside London. While there, his father provided additional impetus, as the two discussed points of the tale, and Stevenson's father was the one who suggested the scene of Jim in the apple barrel and the name of Walrus for Captain Flint's ship.