Thrice is an American rock band from Irvine, California, formed in 1998. The group was founded by guitarist/vocalist Dustin Kensrue and lead guitarist Teppei Teranishi while they were in high school.

Early in their career, the band was known for melodic hardcore punk music based in heavily distorted guitars, prominent lead guitar lines, and frequent changes in complex time signatures. This style is exemplified on their second album, The Illusion of Safety (2002) and their third album The Artist in the Ambulance (2003). Their fourth album Vheissu (2005) made significant changes by incorporating electronic beats, keyboards, and a more experimental sound. In 2007 and 2008, Thrice released The Alchemy Index, consisting of two studio albums that together make a four-part, 24-song cycle. Each of the four six-song EPs of the Alchemy Index features significantly different styles, based on different aspects of the band's musical esthetic which reflect the elemental themes of fire, water, air and earth, both lyrically and musically. The band's seventh album, Beggars, was released on August 11, 2009, and their eighth, Major/Minor on September 20, 2011. The most recent albums feature a refined combination of the band's different experiments and explorations. In 2011, Thrice announced a final tour and an imminent hiatus.

Kensrue and Teranishi decided to reform the band in 2015. In 2016, Thrice released their first post-reunion album, To Be Everywhere Is to Be Nowhere. The band's tenth album, Palms, was released in 2018. Their eleventh studio album Horizons/East was released in September 2021. Each album released by Thrice has had a portion of its sales proceeds donated to a new charitable organization.