• Underground rapid transit system, urban railway
  • London Underground, a metro system that covers the Greater London area
• Resistance movement, dedicated to fighting an invader or the government

In film:

• Underground (1995 film), directed by Emir Kusturica
• Underground (1970 film)
• Underground (1941 film), directed by Vincent Sherman
• Underground (1928 film), directed by Anthony Asquith

In music:

• Underground (Thelonious Monk album), a 1967 jazz recording by Thelonious Monk
• Underground (Keaggy album), a 1983 album by guitarist Phil Keaggy
• Underground (Analog Pussy album), a 2001 album by Analog Pussy
• Underground (Electric Prunes album), a 1967 album by The Electric Prunes
• Underground (soundtrack), soundtrack to the Emir Kusturica film by Goran Bregović
• "Underground" (song), a 1986 single by David Bowie featured in the film Labyrinth
• "Underground" (Ben Folds Five song), a 1995 song by Ben Folds Five
• The Underground (concert venue), a Christian-affiliated concert venue, operated in the Greater Cincinnati area
• Underground Operations, a Toronto-based independent punk rock record label
• Underground Resistance, a musical collective from Detroit, Michigan
• Linkin Park Underground, the official fan club of the band Linkin Park