Green Day is an American rock band formed in Rodeo, California, in 1987. The group became one of the most commercially successful and influential punk rock acts of the modern era, helping bring the sound of the underground California punk scene into the mainstream. Its core lineup consists of vocalist and guitarist Billie Joe Armstrong, bassist and backing vocalist Mike Dirnt, and drummer Tre Cool.
Armstrong and Dirnt began playing together as teenagers in the East Bay area of San Francisco. The band initially performed as Sweet Children before adopting the name Green Day in 1989. Alongside groups such as Operation Ivy and Rancid, Green Day developed within the Bay Area punk community centered on the 924 Gilman Street club in Berkeley. Their early recordings, including the album 39/Smooth and the EPs 1,000 Hours and Slappy, appeared through the independent label Lookout! Records.
The band's second album, Kerplunk, expanded its audience and attracted the attention of major labels. Green Day signed with Reprise Records and released Dookie in 1994. Produced by Rob Cavallo, the album combined fast punk rhythms, sharp guitar hooks, melodic vocals, and unusually direct songwriting. Songs such as "Longview," "Basket Case," and "When I Come Around" became major alternative rock hits, while Dookie eventually sold millions of copies worldwide. Its success placed Green Day at the center of the 1990s punk revival and established a template for later pop-punk bands.
Green Day followed Dookie with a sequence of albums that broadened its musical range. Insomniac retained the band's aggressive edge, while Nimrod introduced more varied arrangements and included the acoustic ballad "Good Riddance (Time of Your Life)." Warning continued that movement toward folk, power pop, and classic rock influences. Although these records did not equal Dookie's commercial impact, they reinforced the group's ability to balance punk energy with accessible songwriting.
The band reached a new creative peak with American Idiot in 2004. Presented as a politically charged rock opera, the album traced the disillusionment of young Americans during the George W. Bush era through characters including Jesus of Suburbia and St. Jimmy. Its singles "American Idiot," "Boulevard of Broken Dreams," "Holiday," and "Wake Me Up When September Ends" made the group central to the political and cultural conversation of the period. American Idiot won the Grammy Award for Best Rock Album, and "Boulevard of Broken Dreams" later won Record of the Year.
Green Day extended its ambitious approach with 21st Century Breakdown in 2009, then issued the three-part project Uno!, Dos!, and Tre! in 2012. Later albums included Revolution Radio, Father of All Motherfuckers, and Saviors, released in 2024. Saviors reunited the band with producer Rob Cavallo and paired contemporary political concerns with a return to the direct, guitar-driven style associated with its best-known work.
Beyond recording, Green Day has maintained a reputation as a forceful live act, moving from small punk clubs to major arenas without abandoning its audience-participation-centered performances. American Idiot was adapted into a Broadway musical in 2009, further expanding the band's influence beyond recorded music. Green Day was inducted into the Rock and Roll Hall of Fame in 2015, its first year of eligibility, recognizing a career that connected underground punk traditions with international popular culture.