"Crazy" is the debut single of American soul duo Gnarls Barkley, taken from their 2006 debut album, St. Elsewhere. It peaked at number two on the Billboard Hot 100 and topped the charts in the United Kingdom, Canada, Ireland, New Zealand, and several other countries.

Gnarls Barkley is an American soul duo composed of singer-songwriter CeeLo Green and producer Danger Mouse. They released their debut studio album, St. Elsewhere, in 2006. It contained their hit single "Crazy", which peaked at number two on the US Hot 100 and topped the UK Singles Chart. It was nominated at the 2007 Grammy Awards for Record of the Year, and was platinum certified for shipping over 1,000,000 records. St. Elsewhere also received a nomination for Album of the Year. The Odd Couple, their second studio album, was scheduled for release in April 2008, but due to a leak of the album over the internet, they decided to release it early. The album in its entirety received similarly positive reviews.