Def Leppard are an English rock band formed in 1977 in Sheffield. Since 1992, the band has consisted of Joe Elliott (lead vocals), Rick Savage (bass, backing vocals), Rick Allen (drums, backing vocals), Phil Collen (guitars, backing vocals), and Vivian Campbell (guitars, backing vocals), which has been the band's longest running line-up. They established themselves as part of the new wave of British heavy metal movement.
The band's greatest commercial success came between the early 1980s and the early 1990s. Their 1981 album, High 'n' Dry, was produced by Mutt Lange, who helped them begin to define their style, and the album's main track "Bringin' On the Heartbreak" became one of the first rock videos played on MTV in 1982. The band's next studio album, Pyromania, was released in January 1983, with "Photograph" and "Rock of Ages" as the lead singles. In the US, Pyromania was certified Diamond, making Def Leppard among the most commercially popular bands at the time.
Def Leppard's fourth album Hysteria, released in 1987, topped the UK and US album charts. As of 2009, it had reached beyond the success of Pyromania, having been certified 12× platinum for sales of over 12 million copies in the US, and has gone on to sell over 25 million worldwide, making it one of the best-selling albums of all time. The album spawned seven hit singles, including the US Billboard Hot 100 number one "Love Bites", alongside "Pour Some Sugar on Me", "Hysteria", "Armageddon It", "Animal", "Rocket", and "Women". Their next studio album, Adrenalize (the first following the death of guitarist Steve Clark), reached number one in UK and US charts in 1992, and contained several hits, including "Let's Get Rocked" and "Have You Ever Needed Someone So Bad". Their 1993 album, Retro Active, contained the acoustic hit song "Two Steps Behind". Their greatest-hits album Vault, released in 1995, featured the UK hit "When Love & Hate Collide".
As one of the world's best-selling music artists, Def Leppard have sold more than 100 million records worldwide, and have two albums with RIAA diamond certification: Pyromania and Hysteria, making them one of only five rock bands with two original studio albums selling more than ten million copies in the US. The band were ranked No. 31 in VH1's "100 Greatest Artists of Hard Rock" and ranked No. 70 in "100 Greatest Artists of All Time". Def Leppard were inducted into the Rock and Roll Hall of Fame in 2019.