Pyromania is the third studio album by English rock band Def Leppard, released on 20 January 1983. It featured new guitarist Phil Collen and was produced by Robert John "Mutt" Lange. The album charted at No. 2 on the Billboard 200 and No. 18 on the UK Albums Chart. It was a huge success, selling over ten million copies in the US, and thus being certified diamond by the RIAA.
The album was partially recorded with original guitarist Pete Willis, whose rhythm guitar tracks appear on all songs.
Midway through the recording sessions, Willis was fired for excessive alcohol abuse and replaced by Phil Collen, who contributed guitar solos and other parts that had not yet been recorded by Willis. On the original LP release, Willis is visible in the background of the photograph of singer Joe Elliott, while Collen is given his own personal photo as the new full-time member of the group.
Pyromania has received mostly positive reviews, being commonly considered, along with its follow-up Hysteria, one of the band's finest efforts to date. Allmusic reviewer Steve Huey gave the album a rating of five stars and stated that it was "where the band's vision coalesced and gelled into something more." He also described the songs as "driven by catchy, shiny melodic hooks instead of heavy guitar riffs, although the latter do pop up once in a while", and later added that "transcendent hard rock perfection on Pyromania was surprisingly successful; their reach never exceeded their grasp, which makes the album an enduring (and massively influential) classic."