Monster a Go-Go! is a 1965 American science-fiction horror film directed by Bill Rebane and Herschell Gordon Lewis. The film is considered to be one of the worst films ever made.

Bill Rebane is an American film director, producer, and screenwriter. He is best known for low budget movies such as Monster a Go-Go and The Giant Spider Invasion. Rebane also ran for Governor of Wisconsin in 1979 and 2002 as the American Reform Party candidate.