Nieuport, later Nieuport-Delage, was a French aeroplane company that primarily built racing aircraft before World War I and fighter aircraft during World War I and between the wars.

Originally formed as Nieuport-Duplex in 1902 for the manufacture of engine components the company was reformed in 1909 as the Société Générale d'Aéro-locomotion, and its products were marketed to the aviation industry, including ignition components. During this time, their first aircraft were built, a small single-seat pod and boom monoplane, which was destroyed in a flood after having flown successfully. A second design flew before the end of 1909 and had the essential form of the modern aircraft, including an enclosed fuselage with the pilot protected from the slipstream and a horizontal tail whose aerodynamic force acted downwards, balancing the weight of the engine ahead of the center of gravity, as opposed to upwards as on contemporaries such as the Blériot XI. Nieuport had trouble obtaining suitable engines for their early designs and resorted to making their own. In 1910 a twin-cylinder horizontally-opposed type producing 28 hp (21 kW) was fitted to the Nieuport II and proved successful. In 1911, the company was reformed specifically to build aircraft while continuing to build components including propellers under the name Nieuport et Deplante. In 1911, Edouard Nieuport(1875–1911), who was one of several aviation minded brothers, died after being thrown from his aircraft, and the company was taken over by Henri Deutsch de la Meurthe, a famous supporter of aviation development. With his financing, the name was changed to Société Anonyme des Établissements Nieuport, and development of existing designs was continued. A second of the brothers, Charles Nieuport, died in another accident in 1912 after he stalled and spun in, and the position of chief designer was taken over by the Swiss engineer Franz Schneider, better known for his work for his next employer, L.V.G., and his long-running fight with Anthony Fokker over machine gun interrupter / synchronizer patents. Schneider left Nieuport in late 1913.

With Schneider's departure, Gustave Delage (no connection to the Delage automobile company) took over as chief designer in January 1914. He began work on a sesquiplane racer - a type of biplane whose lower wing was much narrower in chord than its top wing. This aircraft was not ready to fly until after World War I had begun but, as the Nieuport 10, the type saw extensive service with the Royal Naval Air Service (R.N.A.S.) of the United Kingdom and with the French and Russian Flying Services. The performance of the Nieuport 10, and the more powerful Nieuport 12, which also served with the Royal Flying Corps (R.F.C.) was such that they were used as fighters. Nieuport developed an improved design specifically intended as a fighter - the Nieuport 11, which was regarded as the "baby" (bébé) of the 10, which it closely resembled, except in size. Until the end of 1917, most of the company's output would consist of successive developments of this one design, with more powerful engines, modest increases in overall dimensions, and slightly more refined aerodynamics, until the line ended with the Nieuport 27. As horsepower increased, the "V-strut" Nieuports began to suffer from the limitations of the sesquiplane wing form, and required careful piloting to avoid the risk of wing failures. By March/April 1917 the design was technically outclassed by the newer twin-gun Albatros D.III, and although the process of replacement had already begun, Nieuport 27's would still be in front line service in the spring of 1918. Even while still in frontline service, Nieuports of all types were being used at French and American flight training facilities, with the bulk of production from 1917 onwards going to flying schools. Some pilots, notably Albert Ball and Charles Nungesser, preferred the Nieuport due to its sensitive controls and maneuverability. Pilots Eddie Rickenbacker and Billy Bishop flew Nieuport aircraft to some of their first victories. The first major break from this design, the Nieuport 28 was the first Nieuport fighter with two spars to both upper and lower wings but by the time it was ready for service the French had already chosen the SPAD S.XIII as their primary fighter. Due to a shortage of SPAD S.XIIIs, the first fighter squadrons of the United States Army Air Service (USAAS), used the Nieuport 28 on operations. While only in operational service with the USAAS for a short time, the Nieuport 28 was the first fighter to be used on operations by an American squadron. Nieuports were widely used by the Allied air arms, and various models were built under licence in Italy, Russia and the United Kingdom. In Italy, Aermacchi was originally formed as Nieuport-Macchi for the purpose of building various Nieuports under licence. They started with the Nieuport IV, but built the Nieuport 10, 11, 17 and finally the post-war NiD.29 under license. In Russia several companies, notably Dux, built Nieuports of several types including the IV, 10, 11, 16, 17, 21, 23 and 24bis. In Scotland, the William Beardmore and Company built the Nieuport 12 under licence, while gradually incorporating many of their own changes. Nieuport & General Aircraft was formed to build Nieuport fighters under licence in England, and built 50 Nieuport 17bis scouts for the Royal Naval Air Service before switching to locally designed aircraft. Charles Godefroy flies a Nieuport fighter through the Arc de Triomphe in 1919 On the morning of Friday, 8 August 1919, three weeks after the Paris victory parade in 1919 marking the end of hostilities in World War I, Charles Godefroy flew a "v-strut" Nieuport fighter through the large arch of the Arc de Triomphe in Paris. The event was filmed.