DCU may refer to:

• D.C. United, an American professional soccer team based in Washington, D.C., United States
• DC Universe, the fictional universe that serves as a setting for DC Comics stories
  • DC Universe (franchise), a media franchise
• Dublin City University
  • DCU GAA, a Gaelic games club in Dublin City University
• Digital Federal Credit Union, a credit union based in Marlborough, Massachusetts, United States
• DCU Center, an indoor arena in Worcester, Massachusetts, United States
• Delphi Compiled Unit, an object file for the Delphi programming language
• Desert Camouflage Uniform, a U.S. military uniform that was used in arid areas during the 1990s and 2000s
• Detached Carrier Unit of the United States Postal Service
• Pryor Field Regional Airport, an airport Decatur, Alabama, United States, with the IATA code DCU
• Dicyclohexylurea, an organic compound
• Door control unit, an automative electronic system