Iowa is the second studio album by the American heavy metal band Slipknot. Released by Roadrunner Records on August 28, 2001, it was produced by Ross Robinson and Slipknot. The title derives from the band's home state, Iowa, which members have stated is one of their greatest sources of inspiration. With much anticipation for the album following the success of their 1999 self-titled debut, pressures on the band were high. Their relationships with each other suffered and this was later described as the darkest time of their career. It was also the first full album to feature guitarist Jim Root after only appearing on two songs from their previous album. Despite troubles within the band and with Iowa's development, Slipknot promoted it for almost a year.
Iowa was a major success, premiering in the top tens of nine countries. Generally positively received, it includes some of their notable songs, such as "Disasterpiece", "The Heretic Anthem", "People = Shit" and the Grammy-nominated "Left Behind" and "My Plague". While more technical than their debut, Iowa is considered the band's heaviest and darkest album. It has been certified Platinum in the United Kingdom, the United States and Canada. With a runtime of 66 minutes and 19 seconds, Iowa is the band's longest album. In addition to being their longest album, it also contains their longest song to date, the title track.
 
The first single, "Left Behind", was nominated for the 2002 Grammy Award for Best Metal Performance at the 44th Grammy Awards.[46] The second single, "My Plague", was nominated in 2003 for the same award at the 45th Grammy Awards. The single "Left Behind" peaked in the top thirty for single sales the United States and the UK. In addition, "My Plague" reached the 43rd position on the UK charts. Iowa was ranked sixth in the "50 Albums of the year" by NME in 2001. The album reached the top position on the UK Albums Chart, and the second spot on the ARIA Charts in Australia. The album reached the third spot on the Billboard 200 and the Finnish Albums Chart. On October 10, 2001, the album was certified Platinum in the United States. In Canada, the Canadian Recording Industry Association certified the album as Platinum, on September 5, 2001. The British Phonographic Industry has certified the album as Gold in the UK.
 
In 2009, Iowa was rated third in UK magazine Kerrang!'s "The 50 Best Albums of the 21st century" reader poll. Loudwire listed Iowa at number two in their "Top 11 albums of the 2000s" and number six in their "Top 100 albums of the 21st century". In 2017, Rolling Stone ranked Iowa as 50th on their list of 'The 100 Greatest Metal Albums of All Time.'