¡Uno! is the ninth studio album by the American rock band Green Day, released on September 25, 2012, by Reprise Records. It is the first of three albums in the ¡Uno!, ¡Dos!, ¡Tré! trilogy, a series of studio albums released from September 2012 to December 2012. Green Day recorded the album from February to June 2012 at Jingletown Studios in Oakland, California. This is the band's first album recorded as a quartet, as touring guitarist Jason White joined the band in the studio to give the studio recordings a more live feel.

Green Day is an American rock band formed in the East Bay of California in 1987 by lead vocalist and guitarist Billie Joe Armstrong and bassist and backing vocalist Mike Dirnt, with drummer Tré Cool joining in 1990. In 1994, their major-label debut Dookie, released through Reprise Records, became a breakout success and eventually shipped over 10 million copies in the U.S. Alongside fellow California punk bands Bad Religion, the Offspring, Rancid, NOFX, Pennywise and Social Distortion, Green Day is credited with popularizing mainstream interest in punk rock in the U.S.