The ungainly yet sleek Lockheed P-38 Lightning was the first offering of a military aircraft by what is today is one of the leading defense companies in the world. The P-38 was among the first aircraft to be designed with a twin-boom configuration, with the cockpit and armament housed in a central nacelle. It was powered by two Allison inline engines with turbo-superchargers which made it the first US aircraft capable of exceeding 400 mph. Another rarity among US aircraft was that it was equipped with a 20-mm cannon although this was only a single gun, the remaining armament being 0.50-in Browning machine guns. A large variety of external armament including bombs and rockets could be fitted making it ideal as a fighter-bomber; it's 4,000-lb payload was the same as that of a B-17 on a long-range mission. It was also blessed with impressive range which made it particularly suitable for long-range missions in the Pacific. Unfortunately, in Europe it proved unable to match most German aircraft like the Bf 109 and Fw 190 which prevented it from being used as an effective bomber escort although it was still used extensively as a fighter-bomber and earned it the nickname 'Fork Tailed Devil' by German troops. Against the more lightly armored Japanese aircraft, however, the P-38 excelled in light of its ability to take considerable punishment: the USAAF's two top scoring aces flew Lightnings in the Pacific: Bong (40 kills) and McGuire (38 kills). It was also there in April 1943 where a group of P-38s shot down the aircraft carrying Japanese Admiral Yamamoto over the Solomon Islands, perhaps its most memorable accomplishment during the war although it was also remembered for claiming the first Luftwaffe aircraft by the USAAF: a Fw 200 near Iceland. Aside from its fighter role, the P-38 was used extensively as a photo-reconnaissance aircraft (operated in this role also by Australia, France, and China), a night fighter, and a lead bomber with a Norden bombsight on a modified glazed nose. The P-38 was the only US fighter to be produced throughout the entire war but was phased out of service by the end of the decade, with many aircraft transferred abroad.

The XP-38 prototype was first flown on 27 January 1939. A small number entered service as the P-38 and though it was originally christened 'Atlanta', the USAAF decided to follow the British lead by renaming it with the far better sounding 'Lightning'. Initial variants like the P-38D featured self-sealing fuel tanks, armor protection and a 37-mm cannon which was later replaced by a 20-mm one on the P-38E which was the first to be built in considerable numbers. It was followed by the P-38F which saw extensive service on all fronts though it was recognized to be best suited for the longer distances of the Pacific. Later versions included the P-38G which was the first to include a significant bomb load capacity as well as the P-38H which increased the load and the engine power even more. The ultimate versions of the Lightning began with the P-38J which included new engines which gave it longer contignous power as well as a higher emergency rating. The most produced variant, however, was the P-38L which added with a new turbocharger could reach higher altitutes than its predecessors, both of these last two versions were mass-produced and accounted for over two thirds of all P-38 production. Some P-38Js were modified with a bombardier/navigator position and glass nose for use as bomber leaders, these were known popularly as 'Droop Snoot'. The Lightning was also a highly-successful photo-recon aircraft, known as the F-4 (based on the P-38E and F) and the F-5 (based on the P-38G, J, and L) with numberous subvariants between them. Notably, the French writer Antoine de Saint-Exupéry disappeared flying an F-5 over the Mediterranean in 1944. A P-38M night fighter was also developed with the radar operator located behind the pilot in a raised canopy.