CSU may refer to:

  • Channel service unit, a Wide area network equivalent of a network interface card
  • Chari Aviation Services, Chad, by ICAO airline code
  • Christian Social Union (UK), an Anglican social gospel organisation
  • Christian Social Union in Bavaria, a political party in Bavaria, Germany
  • Civil Service Union, a defunct trade union in the United Kingdom
  • Constant speed unit, a mechanical device on an aircraft propeller that regulates engine speed by automatically changing pitch
  • Crime Scene Unit, a forensic in some police groups this refers to crime scene investigators who respond to a crime scene
  • Český statistický úřad, Czech Statistical Office