Designed by none other than Dr. Barnes Wallis, the Vickers Wellington was the RAF's most successful bomber of the early years and also its most widely produced of the entire war. It was designed to a 1932 requirement and featured a unique geodetic lattice structure which gave it unprecedented ruggedness despite its nickname of "Wimpey". The Wellington was the first RAF bomber to attack Germany but suffered significant casualties during its initial daylight raids because of its poor defensive armament and was subsequently employed mostly as a night-bomber where it became very successful until it was replaced by the four-engined bombers after 1943. During this time, however, the Wellington was involved in operations over Europe, the Mediterranean, and Burma in both bomber and later as a maritime patrol aircraft; its most famous operation was the '1,000 bomber raid' on Cologne in May 1942 of which half of the participating aircraft were Wellingtons. Other users included Australia, Canada and New Zealand.

First flown on 15 June 1936, the Pegasus-equipped Mk. I entered service in late 1938. Subsequent variants differed mostly in power plants, these were the Mk. II with Rolls-Royce Merlins, the Mk. III with Bristol Hercules engines and the Mk. IV with Pratt & Whitney Twin Wasps. The Mk. V and Mk. VI were high-altitude aircraft with pressurized cabins but did not see active service. The ultimate bomber version was the Mk. X with Hercules engines and ended up equipping 25 RAF and allied squadrons. Non-bomber versions of the Wellington served in a bewilering array of roles. These began with the GR.VIII with ASV radar and were followed by the similar GR.XI. The GR.XIII and GR.XIV were torpedo bombers, the latter radar-equipped, while the C.XV and C.XVI were used as transports. Trainers included the T.XVII, T.XVIII and the T.X. which saw service well into the 1950s.