Panic! at the Disco (formerly stylized Panic at the Disco) is an American rock band from Las Vegas, Nevada, formed in 2004. Since its inception, the band's line-up has included Brendon Urie (lead vocals, guitar, piano) and Spencer Smith (drums), and as of 2010, bass guitarist Dallon Weekes.

Founded by childhood friends, Ryan Ross, Spencer Smith, Brent Wilson and Brendon Urie, Panic! at the Disco recorded its first demos while its members were in high school. Shortly after, the band recorded and released its debut studio album, A Fever You Can't Sweat Out (2005). Made known by the top ten lead single, "I Write Sins Not Tragedies", the album eventually was certified double platinum in the US. In 2006, founding bassist Brent Wilson was fired from the band during an extensive world tour, and subsequently replaced by Jon Walker.