The LeO H-246 was designed by the French aircraft manufacturer Lioré-et-Olivier to meet a 1935 specification for a commercial flying boat for use on the Mediterranean routes of Air France.

[1] It was a four-engined parasol monoplane of mixed construction and powered by four 720 hp (537 kW) Hispano-Suiza 12Xir liquid cooled V12 engines.

[2][3] The prototype H-246.01 (Lioré et Olivier's factories had been nationalised at the end of 1936, so the aircraft was built by Sud-Est) made its maiden flight from the Étang de Berre on 30 September 1937.

[4] The third production aircraft was completed for the Navy in June 1940, with a glazed position in the nose for a bombardier/navigator, bomb racks below the wings and four 7.5 mm Darne machine guns as defensive armament.

[4] The German Luftwaffe took over the three seized ex-Air France aircraft, fitting them with five MG 15 machine guns as defensive armament and carrying up to 21 soldiers or 14 stretchers.