Fall Out Boy is an American rock band formed in Wilmette, Illinois, a suburb of Chicago, in 2001. The band consists of lead vocalist and rhythm guitarist Patrick Stump, bassist Pete Wentz, lead guitarist Joe Trohman, and drummer Andy Hurley. The band originated from Chicago's hardcore punk scene and was formed by Wentz and Trohman as a pop-punk side project; Stump joined shortly thereafter. The group went through a succession of drummers before Hurley joined. Their debut album, Take This to Your Grave (2003), became an underground success and helped the band gain a dedicated fan base through heavy touring.

With Wentz as the band's lyricist and Stump as the primary composer, Fall Out Boy's 2005 major-label breakthrough, From Under the Cork Tree, produced two hit singles, "Sugar, We're Goin Down" and "Dance, Dance". It went double platinum, transforming the group into superstars and making Wentz a celebrity and tabloid fixture. Fall Out Boy received a Best New Artist nomination at the 2006 Grammy Awards. Infinity on High (2007) debuted at number one on the Billboard 200 with 260,000 first week sales. It produced two worldwide hit singles, "This Ain't a Scene, It's an Arms Race" and "Thnks fr th Mmrs". Their following album, Folie à Deux (2008), was a commercial disappointment and received a mixed response. Following the release of Believers Never Die – Greatest Hits in 2009, the band went on hiatus and the members worked on side projects.

The band reunited with Save Rock and Roll (2013), which became Fall Out Boy's second number-one album, and included the top 20 single "My Songs Know What You Did in the Dark (Light Em Up)". The same year, the band released the EP PAX AM Days, consisting of eight punk-influenced tracks that were recorded during a two-day session with producer Ryan Adams. The band's sixth studio album, American Beauty/American Psycho (2015) peaked at number one on the Billboard 200, and spawned the top-10 hit "Centuries" and the single "Uma Thurman" which reached No. 22 on the Billboard Hot 100. This was followed by their first remix album Make America Psycho Again, which featured remixes of all original tracks from American Beauty/American Psycho by a different artist on each song, including Migos and Wiz Khalifa.

The band's seventh studio album Mania (2018), also peaked at No. 1, making it the band's fourth No. 1 album and sixth consecutive Top 10 album. The Mania tour included a show at Wrigley Field, marking their first headlining stadium show. In 2018, Fall Out Boy also received their second Grammy nomination for Best Rock Album for Mania. On January 18, 2023, the group announced its eighth studio album, So Much (for) Stardust, which was released on March 24.