FRG

FRG may refer to:
 * Family Readiness Group in the United States Army
 * Federal Republic of Germany
 * West Germany
 * FMN reductase (NAD(P)H)
 * Friendship Radiosport Games
 * Functional renormalization group
 * Guatemalan Republican Front (Spanish: Frente Republicano Guatemalteco), a defunct political party in Guatemala
 * Republic Airport in East Farmingdale, New York, United States