Crowbar is an American sludge metal band formed in New Orleans, Louisiana in 1990. The band is fronted by vocalist/rhythm guitarist Kirk Windstein, Crowbar's sole constant member.

Infusing a slow, brooding doom metal sound with the aggression of hardcore punk, Crowbar along with other bands in the New Orleans heavy metal scene pioneered a style known as sludge metal, though Windstein himself has admitted a dislike for the term. The band has also covered songs from outside of their immediate genre; these include Gary Wright's "Dream Weaver" on Equilibrium, Iron Maiden's "Remember Tomorrow" on Odd Fellows Rest, and Led Zeppelin's "No Quarter" on Crowbar.

The band dates back to 1988, when Kirk Windstein joined the New Orleans hardcore punk band ShellShock. He met Jimmy Bower, who was their drummer, and they quickly became friends. The band collapsed when Mike Hatch, their guitarist, committed suicide in late 1988. The band hence replaced Hatch with Kevin Noonan and continued under the new name, Aftershock. Under that name they released a demo in mid-1989 and then renamed themselves again as Wrequiem, with their bassist Mike Savoie leaving the band and Todd Strange replacing him. They renamed themselves yet again in 1990 as The Slugs, and released a demo in mid-1990, but the band collapsed.

Windstein considered becoming the bass player for New Orleans–based groove metal band Exhorder but he and Strange reformed their band, with Craig Nunenmacher as the drummer. Nunenmacher was later replaced by Tommy Buckley from Soilent Green, and Kevin Noonan returned on guitar. The band renamed themselves Crowbar in mid-1991, after their label warned them that another band called "The Slugs" already existed; the name Crowbar was borrowed from one of Windstein's side-projects. Windstein has listed Celtic Frost as one of the band's early influences in terms of sound.

Crowbar's debut studio album, Obedience thru Suffering, was released in 1991, but failed to achieve significant sales or airplay. 1993's self-titled album, produced by personal friend Phil Anselmo (Pantera, Down, and Superjoint Ritual), eventually led to national promotion on MTV's Headbangers Ball. In addition, the videos for "All I Had (I Gave)" and "Existence Is Punishment" were commented on by Beavis and Butt-Head. Following this success, the band went on to record music videos, embark on major tours with Pantera, and record more albums.

Their stage antics, immortalized in Pantera's third home video and Crowbar's Like Broken Glass home video, became infamous. The band continued recording and touring. In 1994, the Pantera video for the song "I'm Broken" showed Anselmo wearing a Crowbar/Eyehategod T-shirt. Original drummer Nunenmacher left the band in 1996 and was replaced by Jimmy Bower from Down and Eyehategod, and for their 1996 release, Anselmo sang backup on a few tracks on Broken Glass.

In 2000, after recording and releasing Equilibrium with Sid Montz on drums, Nunenmacher rejoined the band for the "Penchant for Violence Tour" with "The Brotherhood of Brewtality" Black Label Society and Sixty Watt Shaman. Halfway through the tour, Nunenmacher replaced BLS's drummer Phil Ondich and pulled double duty for the rest of the tour, eventually joining BLS permanently.

The band continues to perform, borrowing members from New Orleans metal bands like Goatwhore and Acid Bath. In their 2005 release, Lifesblood for the Downtrodden, Pantera bassist Rex Brown lent his bass skills and keyboard playing. Down's producer Warren Riker assisted in production. Also in 2005, Beavis and Butt-Head's commentary on "Existence Is Punishment" appeared on the Beavis and Butt-Head: The Mike Judge Collection No. 3 DVD.