Sleepaway Camp III: Teenage Wasteland (released as Nightmare Vacation III in the United Kingdom) is a 1989 American slasher film and the third installment in the Sleepaway Camp film series. Written by Fritz Gordon and directed by Michael A. Simpson, it stars Pamela Springsteen as Angela Baker, Tracy Griffith, Mark Oliver, and Michael J. Pollard. Taking place one year after the events in the previous film, it again follows the same transgender serial killer, Angela, who is targeting more teenagers at another summer camp.

A fourth film called Sleepaway Camp IV: The Survivor was intended to be released in 1992, but production stopped after the company went bankrupt upon shooting less than forty minutes (which was followed by a DVD release of the footage and one of a cobbled together cut). In 2008, Return to Sleepaway Camp, a direct sequel to the original film was released.