The Beastie Boys were an American hip hop group from New York City, formed in 1980. For the majority of their career, the group consisted of Michael "Mike D" Diamond (vocals, drums), Adam "MCA" Yauch (vocals, bass) and Adam "Ad-Rock" Horovitz (vocals, guitar).

Originally formed as a four-piece hardcore punk band, the Young Aborigines, in 1978 by Diamond (vocals), John Berry (guitar), Yauch (bass) and Kate Schellenbach (drums), the band appeared on the compilation cassette New York Thrash, before recording their first EP, Polly Wog Stew, in 1982. Berry left shortly thereafter, and was replaced by Horovitz. After achieving moderate local success with the 1983 experimental hip hop 12-inch "Cooky Puss", Schellenbach dropped out and the Beastie Boys made a full transition to hip hop, releasing a string of successful singles. They toured with Madonna in 1985 and a year later released their debut album Licensed to Ill. The group sold 26 million albums in the United States and 50 million albums worldwide, making them, according to Billboard, the biggest-selling rap group since the magazine began recording sales data in 1991.

With seven platinum or better albums from 1986 to 2004, the Beastie Boys were one of the longest-lived hip hop acts worldwide. In 2009, they released digitally remastered deluxe editions of their albums Paul's Boutique, Check Your Head, Ill Communication and Hello Nasty. Their eighth studio album, Hot Sauce Committee Part Two, was released in 2011, and received positive reviews. They were inducted into the Rock and Roll Hall of Fame in April 2012, "just the third rap group to enter the Hall, after Run–D.M.C. (2009) and Grandmaster Flash and the Furious Five (2007)." The following month, MCA died of cancer of the parotid salivary gland. In June 2014, Mike D confirmed that he and Ad-Rock would not continue the Beastie Boys, out of respect to MCA.