Weezer were formed in Los Angeles, California, in 1992, and originally consisted of Rivers Cuomo (lead vocals, lead guitar), drummer Patrick Wilson, bassist Matt Sharp, and Jason Cropper (rhythm guitar). Their first gig was opening for Keanu Reeves' band Dogstar, and soon after they began to record their debut album at Electric Lady Studios in New York City. However, during the recording, Cropper left the band, and was replaced by Brian Bell (formerly of Carnival Art). “Weezer”, produced by Ric Ocasek, and often referred to as “The Blue Album”, was released in May 1994, with “Undone – The Sweater Song” as the first official single. “Buddy Holly” was the second single, and the video for the single, directed by Spike Jonze, went on to win 4 MTV Video Music Awards, including “Breakthrough Video” and “Best Alternative Music Video”, and 2 Billboard Music Video Awards. "Say It Ain't So" was the final single released from “Weezer”, an album which was eventually certified triple platinum in the US.

In December 1995, whilst at home on a Christmas break, and using an 8 track recorder, Cuomo began piecing together demo material for a second album, originally mooted as a space-themed rock opera called “Songs from the Black Hole”. In the spring and summer of 1996, the band began to work on this concept in their recording sessions, but eventually dropped the idea, preferring instead to construct the album from songs composed before the band's debut, and new ones written while Cuomo was at Harvard. “Pinkerton” was released in September 1996, produced 3 singles ("El Scorcho", "The Good Life", and "Pink Triangle"), and peaked at number 19 on the US Billboard 200 chart.

Summer 1997 saw Weezer take a break, with Wilson spending some time on his side project, The Special Goodness, Sharp doing likewise with The Rentals, and Bell working on his group, Space Twins. Meanwhile, Cuomo gathered together Boston-area musicians and rehearsed new material, including possible songs for the next Weezer album. The group, sometimes referred to as the Rivers Cuomo Band, had several different lineups (including future Weezer bassist Mikey Welsh) and played shows at local clubs, their first being at T.T. the Bears in October 1997. The Boston songs were later abandoned and not used on the next Weezer album, and in February 1998, Cuomo returned to Los Angeles, where he was joined by Wilson and Bell, but not Sharp, who subsequently left the group, with Welsh his replacement.

In 1998, Weezer covered "Velouria" by the Pixies for a Pixies tribute album, and also contributed the song "Worry Rock" to “Different Shade Of Green: A Green Day Tribute”. The band continued rehearsing and making demos until late 1998, when frustration and creative disagreements led to a decline in rehearsals, culminating in drummer Wilson leaving for his home in Portland, pending renewed productivity from Cuomo. The band did not reunite until April 2000, when the Fuji Festival in Japan offered Weezer a high-paying gig to play in August 2000. This invitation served as a catalyst for Weezer’s productivity, and the band rehearsed and demoed new songs in Los Angeles, returning to live shows in June 2000, playing small unpromoted concerts under the pseudonym ‘Goat Punishment’. Third album, 2001’s “Weezer” (repeating the self titled name of their debut), quickly became known as "The Green Album" due to its distinctive coloring. In August 2001, bassist Welsh was checked into a psychiatric hospital, and, whilst looking for a replacement, Cuomo received Scott Shriner's number via a mutual friend, and asked if he was interested to fill in for Welsh - Shriner accepted.

Weezer took an experimental approach for the recording of their fourth album by allowing fans to download the demos from their official website in return for feedback. However, this approach backfired as the band felt the fans didn’t supply them with cohesive, constructive advice. Cuomo eventually delegated song selection for the album to their original A&R rep, Todd Sullivan (only the song "Slob" was included due to general fan advice). The recording was also done without input from their record label, Interscope (Cuomo had endured what he described as a ‘massive falling out’ with the label). “Maladroit” was eventually released in May 2002, with sales figures below those for its predecessor, "The Green Album" (“Maladriot” remains their lowest-selling album to date). 2 singles were released from the album, "Dope Nose", and "Keep Fishin'". Weezer took a break after the release of “Maladriot”, during which Bell and Wilson released LPs from their respective Space Twins and The Special Goodness side-projects, and a first Weezer DVD was released (in March 2004), entitled “The Video Capture Device”, which chronicles the band from its beginnings through to the tour to support “Maladroit”, and was certified gold in November 2004.

Fifth album, ”Make Believe”, produced by Rick Rubin, was released in May 2005, and first single, "Beverly Hills" became Weezer’s first Billboard Modern Rock chart number 1, achieved the band’s first Grammy nomination (for “Best Rock Song”), and was the second most popular song download on iTunes for 2005 (behind "Hollaback Girl" by Gwen Stefani). The video was also nominated for “Best Rock Video” at the 2005 MTV Video Music Awards. Second single, "We Are All on Drugs", caused a stir as MTV refused to play the song, so Weezer re-recorded the lyrics by replacing ‘on drugs’ with ‘in love’ (thus renaming the song "We Are All in Love"). Third single "Perfect Situation" spent 4 weeks in a row at number 1 on the Billboard Modern Rock chart, and was followed by fourth and final single "This is Such a Pity". In early 2006, ”Make Believe” was certified platinum.

Weezer’s sixth album, their third to be called “Weezer”, but also referred to as "The Red Album", was released in June 2008. Rick Rubin was again on production duties, with the mixing done by Rich Costey. Lead single "Pork and Beans" topped the Billboard Modern Rock Tracks charts for 11 weeks, and its music video won a Grammy for “Best Short Form Music Video”. Second single "Troublemaker" debuted at number 39 on the Billboard Hot Modern Rock Tracks chart, peaking at number 2.

Weezer have sold more than 8 million records in the US to date.