Troy Van Leeuwen (born January 5, 1970) is an American musician and record producer. He is best known as a guitarist and multi-instrumentalist in the rock band Queens of the Stone Age, with whom he has recorded four studio albums. Joining the band in 2002, he is the second longest serving member of the band, after founding member Josh Homme. Leeuwen is also a member of the supergroup Gone Is Gone and has fronted his own projects, Enemy and Sweethead.
Originally a member of Failure, Leeuwen joined the alternative rock supergroup A Perfect Circle in 1999, contributing to their first two studio albums, Mer de Noms (1999) and Thirteenth Step (2003), before joining Queens of the Stone Age to tour in support of their third studio album, Songs for the Deaf (2002). Leeuwen has remained in the band ever since, recording four albums with the band to date: Lullabies to Paralyze (2005), Era Vulgaris (2007), ...Like Clockwork (2013) and Villains (2017).
Leeuwen has contributed to several other Queens of the Stone Age-related side-projects, including The Desert Sessions, Mondo Generator, Eagles of Death Metal and The Gutter Twins. In 2016, Leeuwen was a member of Iggy Pop's touring band, supporting his album, Post Pop Depression (2016), recorded with his Queens of the Stone Age bandmates Josh Homme and Dean Fertita.