Brain Damage is a 1988 American comedy horror film written and directed by Frank Henenlotter. It stars Rick Hearst in his debut acting role as Brian, a young man who becomes acquainted with a talking parasite known as Aylmer (voiced by John Zacherle) that injects him with an addictive fluid that causes euphoric hallucinations; in return, Aylmer demands that Brian allow him to feed on the brains of other humans.

Produced on a budget of under $2 million, Brain Damage is the second feature film directed by Henenlotter, following Basket Case (1982). Principal photography and filming on Brain Damage took place in Manhattan, New York City, in 1987. The film has been characterized as containing themes relating to both drug abuse and sexuality, though Henenlotter has downplayed such interpretations. Along with special makeup and optical effects, the film makes use of mechanical puppetry and stop-motion animation.

Brain Damage received a limited theatrical release, premiering in select theaters in New York City on April 15, 1988, before being released in Los Angeles, California, the following month. The film initially garnered mixed reviews, but quickly acquired a cult following after being released on home video. An uncut version of the film was later issued on DVD and Blu-ray.