"Madhouse" is a song by the thrash metal band Anthrax, off their 1985 album, Spreading the Disease. The song is an up-tempo song with hard riffs and a strong thrash beat. The song has become a staple of live concerts, and has also appeared on Anthrax's 'best of' album, Anthrology: No Hit Wonders (1985-1991). It is included in the 2002 video game Grand Theft Auto: Vice City, on the station "V-Rock". It is also covered in the PlayStation 2 and Xbox 360 video game, Guitar Hero II.

A music video was produced for this song as well, but didn't receive much airplay due to the fact that it was banned by MTV, who believed the content to be degrading to the mentally ill.