Fabrique Nationale Herstal (French for 'National Factory Herstal'), FN Herstal and often referred to as Fabrique Nationale or simply FN, is a leading firearms manufacturer based in Herstal, Belgium. It is currently the largest exporter of military small arms in Europe. FN America is the U.S. subsidiary of FN Herstal, which was formed by the merger of FN's previous two American subsidiaries – FN Manufacturing and FNH USA.

FN Herstal originated in the small city of Herstal, Belgium. The Fabrique Nationale d'Armes de Guerre (French for 'National Factory of Weapons of War') was established in 1889 to manufacture 150,000 Mauser Model 89 rifles ordered by the Belgian government. FN was co-founded by the major arms makers of the Liège region, with Henri Pieper being the driving force and the primary shareholder of the new company. In 1897, the company entered into a long-lasting relationship with John Browning, a well-known American firearms designer.In 1973, FN changed its name to reflect a diversified product line far beyond just military small Arms and firearms manufacturing, adopting the current name of Fabrique Nationale d'Herstal.

Firearms designed and/or manufactured by FN include the Browning Hi-Power and Five-seven pistols, the FAL, FNC, FN 509, FN 503, FNX, FNS, F2000 and SCAR rifles, the P90 submachine gun, the M2 Browning, MAG, Minimi, ,FN Evolys, as well as the M16 rifles, M249 light machine guns, M240 machine guns, and M2 machine guns, all used by the U.S. Military.