The lead guitarist and keyboardist of English alternative rock band, Radiohead, Jonathan Richard Guy Greenwood, better known as Jonny Greenwood in entertainment circles, is an English musician and film composer. He ranked 59th on the Rolling Stone's "100 Greatest Guitarists of All Time" list. Greenwood was originally supposed to play the harmonica in Radiohead but in time he went on to become the lead guitarist, synthesizer, pianist, recorder, and arranger. Radiohead bass player Colin Greenwood is his older brother.

In 2003 Greenwood made his debut as a composer with Simon Pummell's documentary, Bodysong. But it was the 2007 epic drama, There Will Be Blood, that gave Greenwood cult status. It was praised by critics and legendary composer Hans Zimmer called the official soundtrack one of his favorites from the past decade. Greenwood's work on the movie won the Critics' Choice Awards and the Best Film Score trophy in the Evening Standard British Film Awards for 2007. In 2007 he was nominated for Breakout Composer of the Year by the International Film Music Critics Association (IFMCA) for his work on Paul Thomas Anderson's There Will Be Blood. Greenwood next composed for Tran Anh Hung's 2010 movie, Norwegian Wood. The following year he worked on Lynne Ramsay's We Need to Talk About Kevin. In 2012 Greenwood worked on Paul Thomas Anderson's The Master. He re-teamed with Anderson in 2014 for the crime-drama, Inherent Vice. Greenwood's 2017 work on Paul Thomas Anderson's Phantom Thread has been nominated for the Academy Award in the Best Original Score category. The movie will see an Indian release in 2018. Lynne Ramsay approached Greenwood again in 2017 to work on her new movie, You Were Never Really Here.