Sleepaway Camp II: Unhappy Campers (released as Nightmare Vacation II in the United Kingdom) is a 1988 American slasher film written by Fritz Gordon and directed by Michael A. Simpson. It is the second installment in the Sleepaway Camp film series, and stars Pamela Springsteen as Angela Baker, and Renée Estevez. The film takes place five years after the events of the original, and features serial killer Angela, working as a counselor, murdering misbehaving teenagers at another summer camp.

Sleepaway Camp II: Unhappy Campers has elements of black comedy and references various horror franchises, such as Friday the 13th, A Nightmare on Elm Street, and The Texas Chainsaw Massacre.

It was followed by a direct sequel, Sleepaway Camp III: Teenage Wasteland (1989), one year later.