Josephine Sarah Marcus Earp (1861-December 19, 1944) was an American part time actress and dancer who was best known as the wife of famed Old West lawman and gambler Wyatt Earp. Known as "Sadie" to the public in 1881, she met Wyatt in the frontier boom town Tombstone, Arizona Territory when she was living with Cochise County Sheriff Johnny Behan. She became Earp's common-law wife for 48 years.
Much of her life up to about 1882 is uncertain, as Josephine protected many details of her life prior to leaving Tombstone, Arizona, even threatening legal action to keep information private. She became well-known when a manuscript about her life was used as a source by amateur historian Glen Boyer for the book I Married Wyatt Earp, first published by the University of Arizona Press in 1967. The work was considered a factual memoir, cited by scholars, studied in classrooms, and used as a source by filmmakers for 32 years. In 1998, it was found that Boyer could not substantiate many of the facts included, causing some critics to describe it as a fraud and a hoax, and the university withdrew the book from its catalog.