FJ

• 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

• 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

• 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

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

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

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

• 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
• Fulbright & Jaworski, former United States law firm

• FJD (disambiguation)
• FJS (disambiguation)

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