Ann Rae Rule (née Stackhouse; October 22, 1931 – July 26, 2015) was a prominent American author known for her true crime books and articles. She gained fame for her book The Stranger Beside Me (1980), which detailed the life of serial killer Ted Bundy, who was not only her colleague but also her friend.

Raised in an environment surrounded by law enforcement and the criminal justice system, Rule aspired to work in law enforcement herself. She worked as a Seattle Policewoman and was well-educated in psychology and criminology.

Throughout her career, she authored over 30 true crime books, including Small Sacrifices, which focused on Oregon child murderer Diane Downs. Her works often centered on murder cases in the Pacific Northwest and her adopted home state of Washington.

Ann Rule's unique distinction among true crime writers was underscored by the fact that she was a trained volunteer on the suicide hotline at the Seattle Crisis Clinic, working closely with Ted Bundy before his criminal identity was revealed. She received accolades for her work, including two Anthony Awards from Bouchercon, a notable mystery fans' organization.