Heinkel He 112 byla německá stíhačka z první poloviny 30. let, která soutěžila o vládní zakázku na nové stíhací letadlo s uzavřenou kabinou a zatahovacím podvozkem. Byla poražená Messerschmittem Bf 109. V Luftwaffe se nedočkala většího rozšíření, ale byla vyvážena do Maďarska, Rumunska, Japonska a Rakouska. Počet postavených strojů nepřesáhl 100 kusů. V roce 1933 vydalo RLM požadavek na novou stíhačku, která by nahradila starší stíhací dvouplošníky Heinkel He 51 a Arado Ar 68. Návrhy zaslaly firmy Arado, Focke-Wulf, Heinkel a Messerschmitt. Prototyp Heinkelu He 112 byl zkoušen soutěžně spolu s dalšími třemi letouny v Travemünde v říjnu 1935 a spolu s Messerschmittem Bf 109 dostal objednávku na 10 letadel. Prototyp poháněný motorem Rolls-Royce KestrelV, s výkonem 518kW, byl nasledován dvěma dalšími stroji se zmenšeným rozpětím křídel a slabším motorem Junkers Jumo 210C s výkonem 447kW. Čtvrtý prototyp s novým, eliptickým křídlem, byl operačně zkoušen v Legii Condor ve Španělsku v roce 1936, a byl vystaven na letecké výstavě v Zurichu roku 1937. V Španělsku na nich létali civilní piloti a byl hodnocený lépe než Bf 109C.

Late in 1933 the RLM issued a specification calling for a momoplane fighter design.Four designs were produced : Arado 80.the Fw 159,the Bf 109 and the Heinkel 112. The He 112 which was designed by Dipl.Ing Heinrich Hertel, completed with the other three at a competition held at Travemunde in October 1935.The product of the He 112A series was failured and Hertel undretook a complete structural redesing of the aircraft under the deignation He 112B.The first production prototype was the V9,which first flew in July 1937.The Japanese goverment placed an order for thirty He 112 during the autumn of 1937.The He 112B-0 had two 20 mm cannon in the wings and two 7,9 mm MG machine-guns mounted above the engine cowling.The first twelve aircraft were delivered to Japan during the spring of 1938,but a second batch of twelve,were hurriedly impressed into the Luftwaffe because of the Sudeten crisis.The machines were delivered to III/JG 132 at Furstenwalde,but following the signing of the Munich agreement,the fighters were returned to Heinkel for export and immediately offered the to Spain.The seventeen were delivered to grupo 5-G-5 in November 1938.When the Spanish civil War was ended,the fifteen He 112 B-0 were transfered to Spanish Maroco.Royal Rumanian airforce ordered early 1939 twentyfour aircraft of the improved B-1 series.The B-1series was powered by a 700 hp Jumo 210 G engine with direct fuel injection.Twelve aircraft were delivered to each of two unic,the 20th Squadron,engeged in the defence of Bucharest,and the 51th,supported the Rumanian army across Bessarabia from June 1941.By the middle of 1942,remaining He 112 had been relagated to training units.The last airarm to receive the He 112 was the Royal Hungarian Air Force which purchased thry He 112 B-1.