Tesseract (often stylized as TesseracT) are an English progressive metal band from Milton Keynes. The band, formed in 2003, consists of Daniel Tompkins (lead vocals), Alec "Acle" Kahney (lead guitar and producer), James Monteith (rhythm guitar), Amos Williams (bass, backing vocals), and Jay Postones (drums, percussion). The band is currently signed to Kscope. They are credited as one of the bands to pioneer the djent movement in progressive metal. As of 2018, Tesseract have released four studio albums: One, Altered State, Polaris, and Sonder, as well as a live album, Odyssey/Scala, and the extended plays Concealing Fate, Perspective and Errai.
In 2020 Tesseract performed Portals, described as a "live cinematic experience" as a ticketed online stream. Drummer Jay Postones was replaced by Mike Maylan (Monuments) for the event, since Postones chose to stay in Texas due to the necessary 2 week isolation from the coronavirus pandemic.