Deep Purple are an English rock band formed in London in 1968. They are considered to be among the pioneers of heavy metal and modern hard rock, but their musical approach has changed over the years. Originally formed as a psychedelic rock and progressive rock band, they shifted to a heavier sound with their 1970 album Deep Purple in Rock. Deep Purple, together with Led Zeppelin and Black Sabbath, have been referred to as the "unholy trinity of British hard rock and heavy metal in the early to mid-seventies". They were listed in the 1975 Guinness Book of World Records as "the globe's loudest band" for a 1972 concert at London's Rainbow Theatre and have sold over 100 million albums worldwide.

Deep Purple have had several line-up changes and an eight-year hiatus (1976–1984). The first four line-ups, which constituted the band's original 1968–1976 run, are officially indicated as Mark I (1968–1969), Mark II (1969–1973), Mark III (1973–1975) and Mark IV (1975–1976). Mark I comprised the founding members of Deep Purple, Ritchie Blackmore (guitar), Rod Evans (vocals), Jon Lord (keyboards), Ian Paice (drums) and Nick Simper (bass), while Mark II was the most commercially successful line-up, with Ian Gillan (vocals) and Roger Glover (bass) replacing Evans and Simper. Mark III saw David Coverdale (vocals) and Glenn Hughes (bass and vocals) replace Gillan and Glover, while Mark IV featured Tommy Bolin (guitar) replacing Blackmore. Mark II was revived from 1984–1989 and again from 1992–1993, with Joe Lynn Turner (vocals) replacing Gillan in the intervening 1989–1992 period. Mark II definitively ended in 1993, when Blackmore left Deep Purple for the second and final time. He was replaced temporarily by Joe Satriani (guitar) and then permanently by Steve Morse (guitar). In 2002 Don Airey (keyboards) replaced Lord, which saw Deep Purple settle into its longest running line-up, unchanged for the next twenty years, until Morse announced his departure from the band in 2022. His place was taken by Simon McBride (guitar). Ian Paice, Roger Glover, Ian Gillan, Don Airey and Simon McBride comprise the current line-up of Deep Purple.

Deep Purple were ranked number 22 on VH1's Greatest Artists of Hard Rock programme, and a poll on radio station Planet Rock ranked them 5th among the "most influential bands ever". The band received the Legend Award at the 2008 World Music Awards. Deep Purple (specifically Blackmore, Lord, Paice, Gillan, Glover, Coverdale, Evans, and Hughes) were inducted into the Rock and Roll Hall of Fame in 2016.