CTG is an acronym for:
- China Three Gorges Corporation, a Chinese state-owned power company
- Computer Task Group, Incorporated
- Central Economic Society for the Grand Duchy of Poznań (est. 1861, Polish: Centralne Towarzystwo Gospodarcze dla Wielkiego Księstwa Poznańskiego, CTG) - promotion of modern agriculture
- Counter Terrorist Group, a European intelligence sharing forum
- ctg is the notation for Cotangent function, that is used, for example, in Russia
- The IATA airport code for Rafael Nuñez International Airport, in Cartagena, Colombia.
- Center for Technology in Government, a research institution in University at Albany, State University of New York, devoted to improving government and public services through policy, management, and technology innovation.
- Chittagong, Bangladesh
- IBMs Customer Information Control System Transaction Gateway
- CTG is the ICAO airline designator for Canadian Coast Guard
- CTG is the Clinical Trials Group of the Division of Surgery and Interventional Science at UCL 1
- CTG is Cambridge Technology Group.
- CTG is the abbreviation for a particular type of power plant, combustion turbine generator
- Vietinbank (derived from its Vietnamese name)