Thursday is an American post-hardcore band formed in New Brunswick, New Jersey, in 1997. The band consists of Geoff Rickly (lead vocals), Tom Keeley (lead guitar, backing vocals), Steve Pedulla (rhythm guitar, backing vocals), Tim Payne (bass), and Tucker Rule (drums).

The band's debut album Waiting (1999) featured original guitarist Bill Henderson, who left in 2000 and was replaced by Pedulla. Thursday gained popularity with their second album Full Collapse (2001), and the band's major-label debut War All the Time (2003) debuted at number 7 on the US Billboard 200. The band released A City by the Light Divided (2006), Common Existence (2009) and No Devolución (2011) before announcing an indefinite hiatus following Australian tour dates in 2012, which Rickly later confirmed was a full disbandment.

Thursday reunited in 2016, touring for the next few years and breaking up again in 2019. In 2020, Thursday announced another reunion at Chicago's Riot Fest in 2021. In 2024, the band released "Application for Release From the Dream", their first new song in 13 years.

The band is considered influential in the post-hardcore music scene in the 2000s, and is credited as one of the key bands to popularize the darker emo sound and screaming vocals which came to prominence at the time.