FJ

FJ may refer to:

Places

 * Fiji (ISO 3166-1 alpha-2 country code)
 * .fj, the country code top level domain (ccTLD) for Fiji
 * Fijian language (ISO 639-1 language code)
 * Fujian, a province of China

Vehicles

 * FJ Fury, an early Cold War fighter aircraft of the US Navy
 * Flying Junior, a sailing dinghy
 * Holden FJ, an Australian car
 * Jeep FJ, a compact delivery van
 * Toyota FJ Cruiser, a sport utility vehicle
 * Yamaha FJ, motorcycle

Science and mathematics

 * The FASEB Journal, a scientific journal of experimental biosciences
 * Femtojoule (fJ), an SI unit of energy equal to 10−15 joules
 * Fritz John conditions, conditions in optimization problems

Media

 * FictionJunction, a J-pop group
 * The FJ Holden, an Australian film

Military

 * Fallschirmjäger, German paratroopers
 * Fahnenjunker, a military rank of the Bundeswehr
 * FJ ABM, an anti-ballistic missile
 * Young Force (Fuerza Joven), the former youth wing of the Fuerza Nueva
 * Youth Front (Frente de la Juventud), a Spanish terrorist organization

Aviation

 * Fiji Airways (IATA code)
 * Williams FJ33 and FJ44, families of turbofan jet engines

Other uses

 * FJ Management, an American corporation
 * FJ Reitz High School, a public high school in Evansville, Indiana
 * Formula Junior, an auto racing class
 * Sony Vaio FJ, a mid-2000s series of laptops