In 1930, Loire Aviation, a subsidiary of the French shipyard Ateliers et Chantiers de la Loire of Saint-Nazaire, started design of a single-engined flying boat for use as a trainer and a transport in France's overseas possessions.

The resultant aircraft, the Loire 50, was an amphibian high-winged monoplane, with a 230 hp (170 kW) pusher Salmson 9AB radial engine mounted above the wing.

[1] Although it was damaged in an accident in October, it was repaired and entered service in 1932 as a trainer.

It was returned to Loire in February 1933, where it was modified with a more powerful (350 hp (260 kW) Hispano-Suiza 9Qd engine, becoming the Loire 50bis, flying in this form on 18 October 1933.

The Loire 501 remained in service at the start of the Second World War, with the last example still in use at Karouba in Tunisia on 15 August 1940.