Michael Myers is a fictional character from the Halloween series of slasher films. He first appears in John Carpenter's Halloween (1978) as a young boy who murders his older sister, then fifteen years later returns home to murder more teenagers. In the original Halloween, the adult Michael Myers, referred to as "The Shape" in the closing credits, was portrayed by Nick Castle for most of the film, with Tony Moran and Tommy Lee Wallace substituting in during the final scenes. The character was created by Debra Hill and John Carpenter and has appeared in nine films, as well as novels, a video game, and several comic books.

The character is the primary antagonist in the Halloween film series, except Halloween III: Season of the Witch, which is not connected in continuity to the rest of the films. Since Castle, Moran, and Wallace put on the mask in the original film, six people have stepped into the role. Tyler Mane is the only actor to have portrayed Michael Myers in consecutive films, and one of only two actors to portray the character more than once. Michael Myers is characterized as pure evil, both directly in the films, by the filmmakers who created and developed the character over nine films, as well as by random participants in a survey.