Henry: Portrait of a Serial Killer is a 1986 American independent psychological horror film directed and co-written by John McNaughton about the random crime spree of a serial killer who seemingly operates with impunity. It stars Michael Rooker in his film debut as the nomadic killer Henry, Tom Towles as Otis, a prison buddy with whom Henry is living, and Tracy Arnold as Becky, Otis's sister. The characters of Henry and Otis are loosely based on convicted real life serial killers Henry Lee Lucas and Ottis Toole.

The film was shot in 1985 but had difficulty finding a film distributor. It premiered at the Chicago International Film Festival in 1986 and played at other festivals throughout the late 1980s. Following successful showings during which it attracted both controversy and positive critical attention, the film was rated "X" by the MPAA, further increasing its reputation for controversy. It was subsequently picked up for a limited release in 1990 in an unrated version. It was shot on 16mm in less than a month with a budget of $110,000.

The original poster artwork was a painting by Joe Coleman. It was considered too extreme and, after being withdrawn, was replaced by the current official poster.