Cathy's Curse (French: Une si gentille petite fille, lit. Such a sweet little girl) is a 1977 supernatural horror film directed by Eddy Matalon and starring Alan Scarfe, Beverly Murray, and Randi Allen. The film follows a young girl who is possessed by the spirit of her deceased aunt. A co-production between Canada and France, it was shot on location in Westmount and Montreal, Quebec.

Though the film was critically panned upon initial release, with many deriding it as being overly derivative of other films of the period including The Exorcist and Carrie, it has since become a cult classic, some calling the film "so bad it's good".