Innerpartysystem (often stylized as InnerPartySystem) is an American electronic rock band. The group consists of Patrick Nissley, Jared Piccone and Kris Barman. The band is well known for their live performance lighting largely by Andrew Nissley and videos directed by Stephen Penta.

The band was named for a term used in the George Orwell novel Nineteen Eighty-Four.

Their debut EP The Download EP was released in November 2007 and their debut self-titled album in late September 2008. As of late 2008 the band started releasing seasonal mixtapes, new remixes including Ladyhawke's track "Paris Is Burning" and Katy Perry's "Hot n Cold". In May 2009 the band digitally released the UK equivalent of The Download EP, entitled Heart of Fire. As of October 2009, the band worked towards their EP Never Be Content, which was released in February 2011.

After rumours circulated the internet on Jesse Cronan leaving the band, it was confirmed on March 3, 2010 by a blog post by Cronan. Cronan stated that his reasons for leaving were because he felt "unsatisifed and unmotivated".

On August 3, 2011, Innerpartysystem issued a statement that the band was going on indefinite hiatus. They performed their last shows at the end of August.