Green Day is an American punk rock band formed in 1987 in Rodeo, California. The band was founded by lead vocalist and guitarist Billie Joe Armstrong and bassist Mike Dirnt. Drummer Tré Cool joined in 1990, completing the band’s most famous lineup. Green Day is widely credited with popularizing punk rock in the mainstream during the 1990s and 2000s. History Green Day began performing in the late 1980s as part of the East Bay punk scene, playing at venues such as the legendary 924 Gilman Street c