Underoath (styled as Underøath or UnderOath) is an American rock band from Tampa, Florida. It was founded by lead vocalist Dallas Taylor and guitarist Luke Morton in 1997 in Ocala, Florida; subsequently, its additional members were from Tampa, including drummer, singer and last remaining original member Aaron Gillespie. The band's current lineup consists of Gillespie, keyboardist Christopher Dudley, lead guitarist Timothy McTague, bassist Grant Brandell, and lead vocalist Spencer Chamberlain. Originally, the band identified as a Christian group; they have since distanced themselves from Christianity.

The band's lineup shifted frequently during its early years. Taylor recorded Act of Depression, Cries of the Past, and The Changing of Times with the band and remained with the group until his departure in 2003; Chamberlain replaced him as lead vocalist, and the lineup has remained mostly stable since. The band then released They're Only Chasing Safety and Define the Great Line, and both earned gold certifications by the RIAA. These two albums remain their most commercially successful releases, and provided them with mainstream status; the latter of the two holds their highest Billboard 200 entry, peaking at no. 2. Following their sixth studio album, Lost in the Sound of Separation, which also reached a top-ten peak on the Billboard 200, Gillespie left the group and was replaced by former Norma Jean drummer Daniel Davison. Their seventh album, Ø (Disambiguation), was released in 2010; Chamberlain and McTague provided more prominent sung vocals in Gillespie's absence. On October 2, 2012, Underoath announced that they would be disbanding in 2013; they played their final show that January.

On August 17, 2015, the band announced they had reunited; in doing so, Gillespie returned to the lineup. After performing at A Day to Remember's Self Help Fest in 2016, Underoath announced their eighth studio album, Erase Me, would be released 2018. It was their first album in 8 years and their first in 10 years with Gillespie; the band also publicly abandoned their Christian musical approach starting with this record. The follow-up, Voyeurist, was released in January 2022.