Taking Back Sunday is an American rock band from Amityville, New York, formed by guitarist Eddie Reyes and bassist Jesse Lacey in late 1999. The band's current members are Adam Lazzara (lead vocals), John Nolan (lead guitar, keyboards, vocals) and Shaun Cooper (bass guitar), accompanied by Nathan Cogan (guitar) and Mitchell Register (drums) for their live performances. The band's former members include original singer Antonio Longo, Jesse Lacey, Eddie Reyes, drummer Mark O'Connell, bassist Matthew Rubano, and guitarist-vocalists Fred Mascherino and Matthew Fazzi.

Lacey quit Taking Back Sunday in 1999 and in 2000 formed the rock band Brand New, with whom Taking Back Sunday would become embroiled in a highly publicized feud. Lazzara joined prior to the release of the band's 2002 debut album Tell All Your Friends, while Nolan and Cooper left the band in 2003 to form Straylight Run before returning in 2010. The band's breakthrough album, 2006's Louder Now, featured the popular lead single "MakeDamnSure", sold over 900,000 copies, and peaked at No. 2 on the United States Billboard 200, surpassing the band's previous Billboard 200 peak in 2004 at No. 3 with Where You Want to Be. They released their eighth studio album, 152, in 2023.

Taking Back Sunday has been referred to as "one of the more visible groups of the early-2000s emo boom." The staff of Consequence ranked the band at number 38 on their list of "The 100 Best Pop Punk Bands" in 2019.