"Basket Case" is a song by rock band Green Day, released on August 1, 1994 by Reprise Records as the second single from the band's third studio album, Dookie (1994). The song spent five weeks at the top of the US Billboard Alternative Songs chart and garnered a Grammy Award nomination in the category for Best Rock Vocal Performance by a Duo or Group. Its music video was directed by Mark Kohr and filmed in an abandoned mental institution in California. In 2001, the song appeared on their greatest hits album International Superhits!. In 2021, "Basket Case" was ranked number 150 in Rolling Stone's updated list of the "500 Greatest Songs of All Time". As of March 2024, "Basket Case" is the most streamed song by the band on Spotify, with over 1 billion streams.

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.