American hip-hop and rock group, the first white rap performers to gain a substantial following; as such, they were largely responsible for the growth of rap's mainstream audience. The principal members were MCA (byname of Adam Yauch; b. August 5, 1964, New York, New York, U.S.), Mike D (byname of Mike Diamond; b. November 20, 1966, New York), and King AdRock (byname of Adam Horovitz; b. October 31, 1966, New York).

Founded in New York City in 1981 by a group of arty middle-class Jewish kids responding to Manhattan's eclectic downtown music scene, the Beastie Boys evolved by 1983 from a hard-core punk quartet (including original guitarist John Berry and drummer Kate Schellenbach) into a trio—MCA, Mike D, and King AdRock. They signed with Def Jam, and early 12-inch singles and a brief tour with Madonna in 1985 finally brought them press attention. It was not until they toured with popular black rappers Run-D.M.C., however, that the Beastie Boys won credibility with the rap audience. Good timing and a clever blend of hard rock samples and parodic fraternity-boy posturing turned Licensed to Ill (1986) into a smash debut album, confirming the emotional and stylistic affinities some critics found between rap and hard rock. After moving from Def Jam to Capitol Records for their 1989 release, Paul's Boutique, the Beastie Boys strategically appropriated retro-funk influences for their 1990s albums, adding an acoustic dimension to digital sound-collage techniques learned from Rick Rubin and Grandmaster Flash (Grandmaster Flash and the Furious Five). The band's 1998 Grammy-winning album, Hello Nasty, was released on their own label, Grand Royal.