Mule Variations is an album by Tom Waits, released in 1999 on the ANTI- label. It was Waits's first studio album since 1992's Bone Machine (the later The Black Rider was a collection of songs originally written for a play). It won a Grammy Award for Best Contemporary Folk Album and was nominated for Best Male Rock Performance for the track "Hold On". It also sold more than 500,000 copies world wide.

The album was backed by an extensive tour in Europe and North America during the summer and autumn of 1999, which was Waits's first proper tour since 1987. Other promotional stops included a solo performance on VH1 Storytellers.

In 2003, the album was ranked number 416 on Rolling Stone's list of The 500 Greatest Albums of All Time.

All songs by Tom Waits and Kathleen Brennan unless otherwise noted.

As a promotional limited offer, an EP titled Hold On was later released with two of the tracks from the Mule Variations album plus two previously unreleased tracks. Track listing:

The Australian/New Zealand and Japanese releases of the album includes "Buzz Fledderjon" and "Big Face Money" as bonus tracks as tracks number 17 and 18 respectively.

Thomas Alan "Tom" Waits (born December 7, 1949) is an American singer-songwriter, composer, and actor. Waits has a distinctive voice, described by critic Daniel Durchholz as sounding "like it was soaked in a vat of bourbon, left hanging in the smokehouse for a few months, and then taken outside and run over with a car." With this trademark growl, his incorporation of pre-rock music styles such as blues, jazz, and vaudeville, and experimental tendencies verging on industrial music, Waits has built up a distinctive musical persona. He has worked as a composer for movies and musical plays and has acted in supporting roles in films including Paradise Alley and Bram Stoker's Dracula; he also starred in the 1986 film Down by Law. He was nominated for an Academy Award for his soundtrack work on One from the Heart.

Lyrically, Waits' songs frequently present atmospheric portrayals of grotesque, often seedy characters and places—although he has also shown a penchant for more conventional ballads. He has a cult following and has influenced subsequent songwriters despite having little radio or music video support. His songs are best-known through cover versions by more commercial artists: "Jersey Girl", performed by Bruce Springsteen, "Ol' '55", performed by the Eagles, and "Downtown Train", performed by Rod Stewart. Although Waits' albums have met with mixed commercial success in his native United States, they have occasionally achieved gold album sales status in other countries. He has been nominated for a number of major music awards and has won Grammy Awards for two albums, Bone Machine and Mule Variations. In 2011, Waits was inducted into the Rock and Roll Hall of Fame.