FJ

FJ may refer to:

*The Holden FJ, a famous Australian car from the 1950s;
*femtojoule (fJ), an SI unit of energy equal to 10^-15 joules;
*Fiji (ISO 3166-1 alpha-2 country code);
*the IATA code for Air Pacific;
*The racing class Formula Junior
*The FJ Fury, an early Cold War fighter aircraft of the US Navy;
*The Flying Junior, a sailing dinghy;
*The Toyota FJ Cruiser.