Machine Head is an American heavy metal band from Oakland, California. The band was formed in 1991 by vocalist/rhythm guitarist Robb Flynn, who remains the only original member of the band. Machine Head's aggressive musicianship made it one of the pioneering bands in the new wave of American heavy metal. Its current lineup comprises Flynn, bassist Jared MacEachern and drummer Matt Alston. Bassist Adam Duce, lead guitarists Logan Mader, Ahrue Luster and Phil Demmel, and drummers Tony Costanza, Chris Kontos and Dave McClain are former members of the band; Mader and Kontos toured with the band in 2019 and 2020 as part of the 25th anniversary tour for its first album, Burn My Eyes (1994).

Machine Head's first four albums earned the band a growing fan base in Europe, however the band would not have success in the United States until later releases. The band drew controversy with its fourth album, Supercharger (2001), which was released three weeks after the September 11 attacks; its only single, "Crashing Around You", and its music video (which featured burning buildings) was pulled from all media outlets. The band nearly disbanded in 2002 after negotiating off its label Roadrunner Records as a result of the controversy, however the band would eventually re-sign with the label.

Having experimented with elements of groove metal and nu metal in its early releases, Machine Head changed to a more traditional thrash metal sound and longer songs with its sixth album, The Blackening (2007), which drew critical acclaim and was chosen as Album of the Decade by Metal Hammer in 2010; the album's first single, "Aesthetics of Hate", also earned a Grammy Award nomination. The band achieved similar success with its next two albums, Unto the Locust (2011) and Bloodstone & Diamonds (2014), before again experimenting with nu metal on its ninth album, Catharsis (2018). Machine Head reverted to its groove and thrash metal roots with its tenth and most recent album, Of Kingdom and Crown (2022), which was its first concept album.

Machine Head has released ten studio albums, two live albums, one video album, 13 singles and 15 music videos. Four of the band's studio albums have been certified silver in the United Kingdom, and the band's highest peak on the Billboard 200 came with Bloodstone & Diamonds at number 21. As of 2013, the band has sold over three million records worldwide.