RTG may refer to:
- Radio Télévision Guinéenne, national broadcasting company of Guinea
- Radioisotope thermoelectric generator, a nuclear electrical generator
- Regular tree grammar, a formal grammar that describes a set of directed trees
- Renal threshold of glucose, a factor in the medical condition glycosuria
- ReTargetable Graphics, term for use of 3rd party video hardware directly by the AmigaOS
- RTG (trainset), a gas turbine-powered train from France
- Royal Thai Government, the unitary government of the Kingdom of Thailand
- Rubber Tyred Gantry crane