The Prowler is a 1981 American slasher film directed by Joseph Zito, written by Neal Barbera and Glenn Leopold, and starring Vicky Dawson, Christopher Goutman, Lawrence Tierney, Cindy Weintraub, and Farley Granger. The film follows a group of college students in a coastal California town who are stalked and murdered during a graduation party by an apparent World War II veteran who killed his ex-girlfriend in 1945.

Filmed in late 1980 in Cape May, New Jersey, The Prowler was independently distributed by Sandhurst Releasing Corporation. It was not a major commercial success, ranking 135th overall that year at the U.S. box office, and grossing less than $1 million. In some international territories, the film was released under the alternate title Rosemary's Killer in a version that truncated many of its graphic murder sequences.

Though it has received mixed reviews from critics, The Prowler developed a cult following in the years after its release, with praise aimed at its hard-edged violence—showcasing special effects by Tom Savini—as well as its atmosphere. It has been named one of the greatest slasher films of all time by several publications, including Complex and Paste magazine, and is noted as a classic of the slasher film sub-genre. The film has also been compared by a number of critics to another slasher film of the same year with a similar plot, My Bloody Valentine.