Descendents formed during 1977 in the South Bay area of Los Angeles County, California, USA. Their initial formation was as the acoustic duo of Frank Navetta, and David Nolte. Bill Stevenson soon hooked up as their drummer, making the duo into a trio. At the end of 1977, Nolte became bass player for The Last, and that group took precedent over David's commitment to the Descendents, so he was replaced by Tony Lombardo — although David stuck around briefly to sing with the band. Their first release (as a trio, with Navetta and Lombardo handling vocals) was the '' 7-inch in the style of melodic garage pop. For a six-month stretch the band included the female singer, Cecilia Loera. Descendents then enlisted Stevenson and Navetta's classmate and a constant presence at Descendents' rehearsals, Milo Aukerman, as a singer during late 1980. It's at this point the Descendents reappeared as a 'proper' punk band, becoming a major player in the developing hardcore scene of Los Angeles.

Their debut album the following year, '', introduced a strong element of melody and sensitivity that set them apart from most other hardcore bands. Stevenson's songs, in particular, would go onto greatly influence the melodic pop-punk bands of the 1990s, with themes of love, loss and alienation (themes far less common in the punk scene during the early 1980s).

Following the album's release, Milo actually went to college to embark on an education that would take him as far as a doctorate in biochemistry. The band then recruited Ray Cooper (3) to handle vocals, but around this time Bill Stevenson became the drummer with fellow hardcore punks Black Flag. Although the plan was to play in both bands, Black Flag's rigorous touring scheduled proved to be too time-consuming. From 1983 to mid 1985 Descendents gigs were sporadic. There were a few gigs where the band appeared as a 5-piece, with both Navetta and Cooper playing guitar plus Milo on vocals. One show included Navetta (in his underwear), Lombardo and Cooper playing under the name Ascendents. The Descendents did not record again until April 1985, from which they returned with the album ''. This was much more sensitive than 'Milo Goes to College', despite '...Grow Up' including humorous songs such as 'Pervert' and 'No F.B'.

The band's line-up changed around the time 'I Don't Want to Grow Up'. By the time of the recording, Navetta left the band to become a fisherman in Oregon and guitar duties were handled by Ray Cooper. Tony Lombardo left after the recording as touring was incompatible with his career as a postal carrier and the recent purchase of a home. Doug Carrion replaced Lombardo on bass. Lombardo has since stated that leaving the Descendents was "a mistake", because being in the band was the highlight of his life.

Their next album, '' (1986) was not well received by critics, but fans liked it. It was a mix of more 'silly' songs (the last track on the album involving band members farting into microphones and laughing).

After the Summer 'Enjoy!' tour, Ray Cooper got a job working in the emerging software industry, and Doug Carrion left for other projects — eventually ending up in Dag Nasty. By September 1986 Stevenson had invited Stephen Egerton and Karl Alvarez of Salt Lake City's Massacre Guys to replace Cooper and Carrion. With the inclusion of Egerton and Alvarez the permanent line-up of the Descendents was in now place.

The group released the album '' in 1987 which, despite songs like 'Van', 'ALL-O-Gistics' and the one-second 'ALL', was the Descendents' most consistently mature 1980's album — featuring emotional songs like 'Coolidge', 'Cameage' and 'Clean Sheets'.

With the release of the album 'ALL', the Descendents introduced to the world the driving concept behind their career's work (from which the album derives its title). The philosophy of ALL defines quite conventionally as "the total extent". The idea of ALL as a concept beyond this conventional definition is one of endless self improvement. "The total extent" is an all-encompassing greatness, the pursuit of which is endless and impossible, but which is also the source of all real happiness.

Milo left again during August 1987, to pursue graduate studies, so the remaining Descendents joined with singer Dave Smalley under the band name ALL. Stevenson, Egerton and Alvarez continued the legacy until 1996, when the Descendents reformed again with Milo Aukerman, now a full-time research biochemist, to record and tour in support of the album ''.

In 2004 the band released the ' EP and their newest full length album '', which is among their more emotional releases to date. Since then, the Descendents have sporadically performed live and have continued to work on new material when their schedules allow it. In 2002 and 2006, Stevenson, Lombardo, and Navetta got together to record the original songs the Descendents had written during their early years (1977–1980, predating 1982's 'Milo Goes to College'), These songs formed a "Lost Album" that had never been formerly recorded before (released as '' on July 23rd 2021 — with '9th & Walnut' a reference to the location of the band's old practice space). Navetta passed away on October 31st 2008 after a brief illness. Also, a documentary about the band, titled '', was released during 2013. In 2014, the band performed the entire 'Milo Goes to College' album live with Tony Lombardo playing bass. With the consistent line-up of Aukerman, Egerton, Alvarez and Stevenson, July 29th 2016 saw the release of new material in the form of the album '', alongside the EP ''.