Ratt was a 1980s Los Angeles metal band, originally formed in the 1970s as Mickey Ratt by vocalist Stephen Pearcy, guitarist Jake E. Lee, bassist Matt Thorr , guitarist Chris Hagar (no relation to Sammy Hagar) & drummer John Turner . These 5 original members shortened the band's name to "Ratt" in 1980.

They recorded a single "Dr. Rock / Drivin' on E", which was given to fans at early club shows. In 1981 they also had the song "Tell the World" on the first Metal Massacre album, which is also known as the first album to have a Metallica song ("Hit the Lights"). After that, Jake E. Lee, Chris Hagar and Matt Thorr left and formed a band called Rough Cutt. Jake E. Lee was with them for about a year before joining Ozzy Osbourne's band in October 1982. The 3 would be replaced by bassist Juan Croucier (who'd just left the band Dokken) and guitarists Robbin Crosby & Warren DeMartini.

By 1983 when the band released their Ratt EP, Stephen Pearcy (vocals), Robbin Crosby (guitar), Warren DeMartini (guitar), Juan Croucier (bass guitar) and Bobby Blotzer (drums) were soon signed to Atlantic Records and released Out of the Cellar (1984). The album was a huge success, selling millions of copies, as did the single, "Round and Round". Ratt's next album, Invasion of Your Privacy didn't sell quite as well but still went platinum. The band soon gained a reputation for wild shows, and Ratt's following three albums, Dancin' Undercover (1986), Reach for the Sky (1988) and Detonator (1990) did well, going at least in platnum sales.

They broke up late into 1991, after releasing a compilation album Ratt & Roll 81-91. In the early 1990s, grunge music became popular and hair metal bands like Ratt were no longer hip. Pearcy left to form a new band, Arcade , before moving on to another new band, Vertex . DeMartini issued a solo album while the band waited for metal to be popular again. In 1997, the band issued Collage , followed by Ratt , a second self-titled release. Pearcy left the group again, forming two more bands: Vicious Delite and Nitronic , as well as a record label, Top Fuel Records , which released some archived Ratt material and Pearcy solo work. Ratt added Jizzy Pearl , John Corabi and Robbie Crane , continuing to tour. In 2001, Robbin Crosby announced that he suffered from AIDS. He died in 2002.