A product of the arts-oriented Saint Ann's School, Diamond was born in New York City to a Jewish household. In 1979, Diamond co-founded the band The Young Aborigines. In 1981, Adam Yauch, aka MCA, a friend and follower of the band, became their bass player, and on the suggestion of their then-guitar player, John Berry, the band changed their name to the Beastie Boys. By 1983, Adam Horovitz (Ad-Rock) joined, and their sound began to shift away from punk to hip hop.
In 1992, Diamond founded the Beastie Boys' now-defunct record label Grand Royal Records. He is also interested in interior decoration, and designed Brooklyn-themed toile wallpaper; it was used in the renovation of the Marquee nightclub in Chelsea, which reopened in January 2013.
A year after the passing of Yauch in 2012, Diamond told Rolling Stone he was "excited about making new stuff again" and released "Humberto Vs the New Reactionaries (Christine and the Queens Remix)" in July 2013. A remix of Yoko Ono Plastic Ono Band's "Bad Dancer" by Diamond and Adam Horovitz was streamed online in August 2013. The pair is credited with "additional beats, programming and other curve balls". In October 2014, Diamond stated that he had been working in the studio with American rock band Portugal. The Man as a Producer. He has also produced English punk outfit Slaves' second studio album, Take Control, which was released on September 30, 2016.
