System of a Down, sometimes simply refered to as SOAD or SoaD, is a Grammy award winning Armenian-American rock band from Glendale, California, formed in 1994. System of a Down consists of Serj Tankian (lead vocals and keyboards), Daron Malakian (vocals and guitar), Shavo Odadjian (bass), and John Dolmayan (drums).

The band has released five studio albums and have sold over 20 million records worldwide. They have been nominated for four Grammy Awards, of which they have won one in 2006 for Best Hard Rock Performance.

System of a Down are noted for the left-wing political views expressed in their songs, tackling several subjects including the Armenian Genocide, war on drugs, religion, and censorship. The band is a part of the Axis of Justice, a non-profit organization co-founded by Tankian and fellow musician Tom Morello, dedicated to bringing together musicians, music fans, and grassroots political organizations to fight for social justice.

System of a Down went on hiatus in 2006, with Serj Tankian pursuing a solo career and Daron Malakian and John Dolmayan forming Scars on Broadway. Shavo joined together with RZA from the Wu-Tang clan to form Hip-Hop group achozen. They hope to release their album towards the end of 2009.