Monsters Crash the Pajama Party is a 1965 American short horror comedy film directed by David L. Hewitt. The film follows a group of young adults who intend to spend a night in a supposedly haunted house, where a mad scientist is conducting experiments to transform humans into gorillas.

Monsters Crash the Pajama Party features an interval in which, during its original theatrical run, costumed actors would appear to exit the film and move about the viewing audience, before ultimately abducting a planted "victim" from the audience and appearing to bring them back into the film. The short screened as part of a traveling midnight ghost show by stage illusionist and promoter Joe Karston, and was followed by a feature presentation.