Loire Aviation was a French aircraft manufacturer in the inter-war period, specializing in seaplanes, and based in Saint-Nazaire, France.
Loire was founded in 1925 as a division of Ateliers et Chantiers de la Loire, a ship-building company based at St Nazaire. ACL were interested in diversifying into the new area of naval aviation, combining its knowledge of metal work and naval construction to produce seaplanes for the French mail service. The company started as a joint venture between ACL and Gourdou-Leseurre, contracting to build 257 GL 32’s under licence at a new factory at St Nazaire. In 1928 they disassociated, in 1930 the company became Loire Aviation, working on own designs by designers Asselot, Jarrion, and Guegand Kerguistel. During this period Loire built some 232 units of their Loire 11 seaplane, as well as aircraft for other companies, and produced a range of aircraft under the Loire marque.
In 1933 the company united with Nieuport, (by then known as Nieuport-Astra) though both companies maintained their own factories and test sites; Loire at St Nazaire and La Baule, Nieuport at Issy-les-Moulineaux and Villacoublay. This led to some complications; the two companies found themselves competing over a contract for a fighter for the French Air Force, later won by Morane Saulnier with the MS 406. The two companies underwent a full merger in 1935 to form the Société Anonyme Loire-Nieuport(SALN), or Loire-Nieuport. In 1936 Loire-Nieuport was nationalized and united with Breguet of Bouguenais, near Nantes, to form the Société Nationale des Constructions Aéronautiques de l'Ouest (SNCAO).