GRT may refer to:

  • Grease Removal Technology, or GRT- Lipase enzyme
  • General Recorded Tape, aka GRT Corporation, a defunct corporation that owned Chess Records and Janus Records as well as being a label in its own right
  • General relativity theory
  • Gross receipts tax, a tax levied on the gross revenue of a company
  • Gross Register Tonnage, a measure of the cargo capacity of a ship
  • GRT Corporation, an American IT services provider headquartered in Stamford, CT
  • Grand River Transit, a regional transit authority in the Region of Waterloo, Ontario, Canada
  • Granular Recovery Technology