Underworld are a British electronic music group formed in 1987 in Cardiff, Wales and the principal collaborative project of Karl Hyde and Rick Smith. Prominent former members include Darren Emerson, from 1990 to 2000, and Darren Price, as part of the live band from 2005 to 2016.

After briefly performing as a funk and synth-pop outfit, resulting in two albums between 1988 and 1989, Underworld gained prominence after reshaping into a dance and techno band, releasing albums including Dubnobasswithmyheadman (1994), Second Toughest in the Infants (1996) and Beaucoup Fish (1999), as well as singles "Born Slippy Nuxx" and "Dark & Long (Dark Train)". Known for their atmospheric, progressive compositions, Hyde's cryptic and stream of consciousness lyrics, and dynamic live performances, Underworld have influenced a wide range of artists and have been featured in soundtracks and scores for films, television, and the 2012 Summer Olympics in London.