Rancid is an American punk rock band formed in Berkeley, California in 1991. Founded by 1980s punk veterans Tim Armstrong and Matt Freeman, who previously played in the highly influential ska punk band Operation Ivy, Rancid is often credited, along with Green Day and the Offspring, for reviving mainstream interest in punk rock in the United States and bringing punk rock into the mainstream during the mid-1990s. Over their 25-year career, Rancid remained signed to an independent record label and retained much of its original fan-base, most of which was connected to its underground roots.

Rancid has had only a few lineup changes since its inception, with Armstrong and Freeman being the only constant members. Their current lineup consists of Armstrong on guitar and vocals, Freeman on bass and vocals, Lars Frederiksen on guitar and vocals, and Branden Steineckert on drums. The band was formed by Armstrong, Freeman, and former drummer Brett Reed, who left the band in 2006 and was replaced by Steineckert. Frederiksen joined Rancid in 1993 when the band was searching for a second guitar player.

To date, Rancid has released eight studio albums, one split album, one compilation, two extended plays, and a series of live online-only albums, and has been featured on a number of compilation albums. The band has independently sold over four million records worldwide, making it one of the most successful independent punk rock groups of all time. The band rose to fame in 1994 with its second studio album, Let's Go, featuring the single "Salvation". In the following year, Rancid released its highly successful album ...And Out Come the Wolves, which produced its best-known songs "Roots Radicals", "Ruby Soho" and "Time Bomb", and was certified gold and platinum by the RIAA, selling over one million copies in the United States alone. Its next four albums — Life Won't Wait (1998), Rancid (2000), Indestructible (2003) and Let the Dominoes Fall (2009) — were also critically acclaimed, though not as successful as ...And Out Come the Wolves. Rancid released ...Honor Is All We Know, their first studio album in five years, on October 27, 2014. They are currently working on a new album. As of 2016, Rancid has been posting pictures of them in the recording studio.