XYZ is a hard rock band, formed in the late 1980s. XYZ started off as the unofficial house band of "The Whiskey", a nightclub in Los Angeles. The original members were, Terry Ilous (vocals), Bobby Pieper (guitars), Patt Fontaine (bass) and Joey Pafumi (drums). A tour of the US with Enuff Z'Nuff and Alice Cooper followed the success of their 1989 Enigma released debut album, and they were signed by major label Capitol for their second.

The band played clubs throughout the mid 1980s and first got a record deal in 1989 with Don Dokken as their producer. Terry Ilous's vocal style on the band's first album was very similar to Dokken's. Ilous and Fontaine then recruited Mark Diglio (guitars) and Paul Monroe (drums) to record a debut album, produced by Don Dokken. The album was released in 1989 and contained the hits "Inside Out" and "What Keeps Me Loving You". Videos for both songs received reasonable airplay, however, the album itself was not an overall success, managing to reach only No. 99 on the Billboard charts. Single "Maggy" was used in the 1990 Dolph Lundgren movie I Come in Peace. The next album, Hungry, released in 1991, had even less commercial success—not charting at all. Diglio and Monroe left the band and were replaced by Tony Burnett and Joey Shapiro, respectively. After the next tour was finished, band members went separate ways once again. They have reunited in various incarnations several times since then.