Ann Rae Rule (née Stackhouse; October 22, 1931 – July 26, 2015) was a renowned American author specializing in true crime books and articles. She gained fame with her book The Stranger Beside Me (1980), which explored the life of the infamous American serial killer, Ted Bundy. Intriguingly, Bundy was both her co-worker and one-time friend while working as a trained volunteer on a suicide hotline at the Seattle, Washington Crisis Clinic.

Raised in a law enforcement environment, Rule initially aspired to pursue a career in law enforcement. She was a former Seattle policewoman and was well-educated in psychology and criminology. Over her career, she authored over 30 books, including the notable Small Sacrifices, which delved into the case of Oregon child murderer Diane Downs. Many of her works focused on murder cases in the Pacific Northwest, particularly her adopted home state of Washington.

Ann Rule's contributions to the genre were recognized with accolades, including two Anthony Awards from Bouchercon, the mystery fans' organization.