FRG may refer to:
- FRG™ - Free Radical Gasification, a carbon conversion process developed by Responsible Energy Inc.
- Family Readiness Groups in the United States Army (formerly known as the Family Support Groups or FSG)
- Federal Republic of Germany, the official name of Germany since 1949. Even though the abbreviation still applies, FRG is mainly used to describe the history of the state (often called West Germany) from 1949 to 1990 until the socialist East German Democratic Republic (GDR) ceased to exist in 1990.
- Freyung-Grafenau, a district in Eastern Bavaria
- Friendship Radiosport Games, a multi-sport event that has been held since 1989
- Functional renormalization group, a method in theoretical physics
- Guatemalan Republican Front (Spanish initials), a right-wing political party in Guatemala
- IATA code of Republic Airport in East Farmingdale, New York, United States
- Flood Resilience Group, a UNESCO center for research on Flood Management