The Loire-Nieuport LN.40 aircraft were a family of French naval dive-bombers for the Aeronavale in the late 1930s, which saw service during World War II.

Between 1932 and 1936, Nieuport-Delage had been developing a two-seat dive bomber, the Nieuport Ni.140, for the Aéronautique Navale, the aviation arm of the French Navy.

Development efforts were then concentrated on the LN.40 project which benefited from experience with the LN.140, but was a new, and aerodynamically more refined design, replacing the fixed and spatted undercarriage of the LN.140 with rearward retracting main gear legs, and dispensing with the second crewman.

The final development was the LN.42 dispensed with the inverted gull wing and elevator endplates and used the much more powerful 1,100 hp (820 kW) Hispano-Suiza 12Y-51 engine but was too late for the Second World War, making only a few short hops before France fell during the 1940 invasion of France when it was hidden from the Germans for the duration of the war.

[3] Both used the type in combat during the Battle of France in ground attacks against German motorized columns and troop concentrations.

The production rate of the LN.401 and LN.411 was insufficient to replace losses, and in about a month of fighting the two squadrons lost two-thirds of their strength.