"American Idiot" is a song by American alt-rock band Green Day, and is the first single from their seventh album, American Idiot.

Released in 2004, the single peaked at #61 on the Billboard Hot 100, becoming Green Day's first chart entry (previous singles had not charted), helping revive the band's career. However, the appearance of "American Idiot" on the US singles charts occurred just prior to Billboard Magazine's inclusion of internet download purchases into their Hot 100 chart data, which would have made a significant difference in the song's peak had it benefited from the new chart tabulation system. This most recent form of sales assessment has resulted in the far greater successes of "Boulevard of Broken Dreams", "Holiday" and "Wake Me Up When September Ends".

"American Idiot" became Green Day's first Top 5 single in the United Kingdom, reaching #3, and peaked at #7 in Australia. It debuted at #1 in Canada, holding onto the zenith position for five weeks.

The song was featured in the trailer for the 2005 film Wedding Crashers. The song features on the soundtrack of the American football video game Madden NFL 2005. It was featured as the closing theme song for the first season of the "Andy Milonakis" show. "Weird Al" Yankovic parodied the song on his album Straight Outta Lynwood as "Canadian Idiot" - a satirical commentary on American nationalism and the stereotypical American view of Canadians. In The Simpsons Movie, after Green Day dies after falling in the highly polluted Lake Springfield, "American Idiot" is played at the band's funeral, with a shot of the sheet music listing the song as American Idiot - Funeral Version.

Richard Cheese and Lounge Against the Machine covered this song into a lounge style on their 2005 album Aperitif for Destruction and Avril Lavigne did as well in 2006.