Lesser known than the ungainly Amiot 143, the Amiot 350 series were actually highly attractive and elegant bombers that began life as a long-range mail carrier. Designed as a high-set cantilever monoplane with wide-span ailerons, split trailing-edge flaps, and a various tail configurations, they were unfortunately was one of the most notorious examples of official government disinterest which would have dire consequences various years later. In the event, none were available at the outbreak of the war and by the time of the German invasion, only a few dozen were operational where they saw action over the Low Countries and were set to engage the Italians in Africa before being sent back to Metropolitan France and disbanded after the surrender. A few continued to be used as transports by Air France between Vichy France and overseas territories while also being operated by the Luftwaffe in small numbers.

First flight of the Amiot 340 prototype first flew on 6 December 1937 with the initial production version being known as the Amiot 351 which had the twin-fin tail unit of the prototype. This was later changed to a single-fin design in the Amiot 354 which eventually became the most widely produced variant. Other versions included revised powerplants including Rolls-Royce Merlin engines in the Amiot 356 while a high-altitude prototype with a pressurized cabin became known as the Amiot 357.