Nightmare is a 1981 American psychological slasher film written and directed by Romano Scavolini, and starring Baird Stafford and Sharon Smith. Its plot follows a deranged man who, after undergoing an experimental medical procedure, is released from a New York City psychiatric hospital and embarks on a road trip to Florida with the intent of murdering his ex-wife and child.

Scavolini, an Italian director who had previously worked making experimental films, developed the idea for Nightmare after reading newspaper articles about psychiatric patients who had been administered powerful drugs that altered their behavior. He completed the film's screenplay over a two-week period while vacationing in Cocoa Beach, Florida, where he chose to set the majority of the film. The film was shot on location in Florida and New York City in late 1980.

Released by 21st Century Film Corporation in the fall of 1981, Nightmare was met by significant criticism for its graphic violence and sexuality: The Motion Picture Association of America granted it an X rating, and it was later banned in the United Kingdom (where it was released under the alternate title Nightmares in a Damaged Brain) and prosecuted for obscenity as a "video nasty". Three executives for the film's British distribution company faced legal action for releasing the film in its original cut, violating the ruling of the British Board of Film Classification, which mandated that approximately 48 seconds of footage be excised before the film could be screened for the public. In 1984, all three executives were found guilty, two of them sentenced to 18 and 9 months imprisonment, respectively.

The film also garnered controversy for claiming in its press material that Tom Savini had provided the film's special effects, which Savini vehemently denied.