Troy Dean Van Leeuwen (born January 5, 1968 in Los Angeles, California) is an American musician and producer. Van Leeuwen began playing music at young age and started playing guitar at age 13. Soon Van Leeuwen was playing in various local bands such as Jester, 60 Cycle and later Failure. During this time, Van Leeuwen also worked as a session musician for various bands and met guitarist Billy Howerdel, who later recruited Van Leeuwen to play guitar in his and Tool frontman Maynard James Keenan's alternative rock supergroup A Perfect Circle. The band's debut album Mer De Noms became the highest ever debut for a rock band, with 188,000 copies sold in its first week.
After recording three tracks on A Perfect Circle's second album, Van Leeuwen successfully auditioned for Josh Homme's Queens of the Stone Age, and was welcomed into the band as their second guitar player. In addition to guitar, Van Leeuwen was also required to play lap steel and keyboards. Since joining the band in 2002, Van Leeuwen has recorded two studio albums - Lullabies to Paralyze in 2005 and Era Vulgaris in 2007 - as well as recorded with various band members' side projects such as The Desert Sessions, Mondo Generator, Eagles of Death Metal and The Gutter Twins. He created his first side project Enemy in 2005, but currently is with his new side project, Sweethead.