Demon Attack is a video game written by Rob Fulop and published by Imagic. It was originally for the Atari 2600, then ported to the Intellivision, Odyssey², Atari 8-bit family, VIC-20, Commodore 64, PC (booter), TRS-80 and TRS-80 Color Computer. There was also a port to the TI-99/4A titled Super Demon Attack.
Demon Attack is supposedly based on the 1979 arcade shooter Galaxian, though it closely resembles several waves from the 1980 arcade game Phoenix. The similarities prompted a lawsuit from Atari, who had purchased the latter's home video game rights. Imagic settled out of court, and Demon Attack became Imagic's best-selling game as of 1983.