"Wake Me Up When September Ends" is a song by American rock band Green Day, released on June 13, 2005, as the fourth single from the group's seventh studio album, American Idiot (2004). The ballad was written by frontman Billie Joe Armstrong about the death of his father when he was 10 years old.

American Idiot is the seventh studio album by the American rock band Green Day, released on September 21, 2004, by Reprise Records. As with their previous four albums, it was produced by Rob Cavallo in collaboration with the group. Recording sessions for American Idiot took place at Studio 880 in Oakland and Ocean Way Recording in Hollywood, both in California, between 2003 and 2004. A concept album, dubbed a "punk rock opera" by the band members, American Idiot follows the story of Jesus of Suburbia, a lower-middle-class American adolescent anti-hero. The album expresses the disillusionment and dissent of a generation that came of age in a period shaped by tumultuous events such as 9/11 and the Iraq War. In order to accomplish this, the band used unconventional techniques for themselves, including transitions between connected songs and some long, chaptered, creative compositions presenting the album themes.