Daniel James Irving (born April 16, 1969), better known as Dan Druff, is a guitar technician and musician who has worked with various artists in the studio and on tours, including Queens of the Stone Age, Guns N' Roses, Tool, Sum 41, Wolfmother, The Distillers, Coheed and Cambria, Monster Magnet and Madrugada.

[3] Druff was born in New Haven, Connecticut and formed the St. Louis rock band Shagnaps in 1991.

[4] In early 2004, bassist Nick Oliveri was fired by frontman Josh Homme and replaced by Druff.

[4] Druff worked on the band's following album, Lullabies to Paralyze, as a technician and appears in the "Little Sister" promotional video.

[6] In 2019, Druff worked as technician on Tool's Fear Inoculum album.