Ms .45 (also known as Angel of Vengeance or Ms. 45) is a 1981 American exploitation thriller film directed by Abel Ferrara and starring Zoë Tamerlis.

Inspired by films such as Thriller – A Cruel Picture (1973), Death Wish (1974), and Taxi Driver (1976), the film is a rape and revenge story about Thana, a mute woman who becomes a spree killer after she is raped twice in one day when going home from work. It was critically detested on its theatrical release, but is now generally highly regarded among fans of underground and independent film.

It was acquired by Alamo Drafthouse Films in October 2013 and remastered in HD from the original negatives. The distributor released the film on Blu-ray, DVD, and digital copy in March 2014.