Phish is an American rock band noted for their musical improvisation, extended jams, blending of musical genres, and dedicated fan base. Formed at the University of Vermont in 1983 (with the current line-up solidifying in 1986), the band's four members—Trey Anastasio (guitars, lead vocals), Mike Gordon (bass, vocals), Jon Fishman (drums, percussion, vocals), and Page McConnell (keyboards, vocals)—performed together for over 20 years before going on hiatus in August 2004. They reunited in March 2009 for Phish in Hampton, a series of three consecutive concerts played in the Hampton Coliseum in Hampton, Virginia, and have since resumed performing regularly.

Phish's music blends elements of a wide variety of genres, including rock, jazz, progressive rock, psychedelic rock, hard rock, funk, folk, bluegrass, and blues. Due to the band's improvisational style, their concerts are original in terms of the order and selection of songs and the way each song and set are performed.