Slipknot is an American heavy metal band from Des Moines, Iowa, formed in 1995. Slipknot consists of nine members. The current band members are Sid Wilson, Joey Jordison, Paul Gray, Chris Fehn, Jim Root, Craig Jones, Shawn "Clown" Crahan, Mick Thomson, and Corey Taylor. Each member of the band wears a unique mask.

Slipknot formed in 1995 and underwent several line-up changes following the independent release of their first demo Mate. Feed. Kill. Repeat. in 1996. That album featured original lead vocalist, Anders Colsefini. Their self-titled, major label debut, Slipknot, was released in 1999, featuring permanent new lead vocalist, Corey Taylor, and was followed by Iowa in 2001 and Vol. 3: (The Subliminal Verses) in 2004. On August 25, 2008, the band returned to release their fourth studio album, All Hope Is Gone, which debuted at the top spot on the Billboard 200 charts. The band has released three DVDs, including Disasterpieces, which was certified quadruple-platinum in the United States. Slipknot have sold over 14 million records worldwide.

The band has stated that their primary influences include Kiss, Black Sabbath, Slayer, Judas Priest, Korn, White Zombie, Led Zeppelin and Beastie Boys. Death metal, black metal and heavy metal have been mentioned as a key influence on the band's musical direction alongside nu metal, the category the band is generally listed as. They have also stated that they are influenced by industrial bands like Head of David, Godflesh and Skinny Puppy as well as Neurosis and jungle music like Roni Size.

Slipknot are seen as pioneers of the New Wave of American Heavy Metal developing a lean and aggressive brand of metal formed from thrash metal, metalcore as well as death metal. In this they can be compared with groups such as Pantera, Machine Head, Biohazard, Life of Agony, and Prong and are known for often chaotic and energetic live shows. The extreme performance style provided by their large line-up featuring a typical heavily down-tuned guitar set-up (lead, rhythm, and bass guitars), two percussionists in addition to the primary drummer, and electronics (samplers and turntables). Robert Cherry of Rolling Stone compared the band's sound to "a threshing machine devouring a military drum corps".

Their early work hosted a diverse range of vocal styles, ranging from growled vocals, rapping and occasional melodic singing. In more recent work, this vocal style remains present, but now includes more melodic singing as well as less rapping. The lyrics generally follow a very aggressive tone and feature themes such as darkness, nihilism, anger, disaffection, love, misanthropy and psychosis. Rick Anderson of Allmusic regards the group's lyrics as "not generally quotable on a family website". There has been controversy surrounding Slipknot's lyrics, including a case in which a pair of young killers blamed the lyrics from the song "Disasterpiece" for their vicious crime and a case in 2006 in which lyrics from the song "Surfacing" were found at the site of a grave robbing.

The band is known for its attention-grabbing image: the members wear matching jumpsuit uniforms, and each one has a unique mask. In the past, their jumpsuits have featured large UPC barcodes printed on the back and sleeves, which are identical and render the same barcode number to the barcode on their first demo, Mate. Feed. Kill. Repeat. Aside from their real names, members of the band are referred to by numbers zero through eight.

With each new album, Slipknot has used new masks and coveralls. The masks have not changed dramatically with the release of their second and third albums, as the masks are more of an extension of what they previously were. Jordison addressed the issue in an interview in 2004, stating that the change in masks are to show growth and difference within age. During the music video and live performances of their single "Vermilion" the band change their respective masks to death masks made from casts of their own faces. Also in 2004, Gray claimed that the special effects company Screaming Mad George made their masks from their third album cycle, and pictures of the band's masks from their second album cycle can be found on the SMG website.

The masks have been subject of much criticism, generally thought of as a gimmick to try sell their product. The band strongly objects to these claims, proclaiming that the masks are used to draw the attention away from themselves and put it on the music. Several members have said how the masks are a visual representation of how the music makes them feel and how they put the members in an animal-like mentality. The coveralls and numbers are an extension of the anti-image concept they created with the masks. The integrity of the masks is also a topic of criticism as band members have appeared outside of Slipknot without the masks. The issue has been addressed by most band members. Percussionist Crahan specifically addressed the issue during an interview on The Sauce when discussing the release of their 2006 DVD Voliminal: Inside the Nine, proclaiming that the masks are always going to be part of the Slipknot show. Purgatory masks

Beginning on April 1, 2008, Slipknot's official website began to display splash teasers to promote All Hope Is Gone. During the process there had been around 18 splash teasers, the first nine displayed the band in their new large masks, however the last seemingly showed dark figures with what seemed like ordinary size heads. During the recording of the video shoot for Psychosocial, the purgatory masks could be seen being burned in the background. An interview with Jim Root revealed that "they represent the ego of that is Slipknot".