The Su-2 was a late-1930s aircraft intended as a fast lightweight monoplane bomber similar to the Fairey Battle, it was the first aircraft designed by Pavel Sukhoi. Though promising, when the war broke out it was found to be extremely vulnerable to enemy fighters despite armor protection for pilot and gunner and although it received some major upgrades it was eventually retired from production in 1942 in favor of newer and more rugged designs like the superb Il-2 and the Pe-2 for which enormous manufacturing facilities had been prepared. Nevertheless, many Su-2s continued to serve in secondary roles as its limited armament and armor gave it few chances of survival in a modern battlefield especially against the threat of Luftwaffe fighters during the initial months of the war when it was even used as a fighter itself due to the shortage of such aircraft.

The prototype ANT-51 first flew in August 1937 with an M-67 radial which was based on the US Wright Cyclone. Its designation reflected the fact that Pavel Sukhoi worked at the Tupolev bureau at the time of its design. A new powerplant was added and entered production as the BB-1 but proved to be woefully inadequate in the face of enemy air superiority and thus, another major engine upgrade resulted in the definitive Su-2 variant.