The German Type IXA submarine was a sub-class of the German Type IX submarine built for Nazi Germany's Kriegsmarine between 1937 and 1938. These U-boats were designed between 1935 and 1936 and were intended to be fairly large ocean-going submarines. The inspiration for the Type IXA submarine came from the German Type IA submarine, which had a similar diving depth and identical submerged horsepower.

German submarine U-37 was a Type IXA U-boat of the German Navy (Kriegsmarine) during World War II. The submarine was laid down on 15 March 1937 at the DeSchiMAG AG Weser yard in Bremen, launched on 14 May 1938, and commissioned on 4 August 1938 under the command of Kapitänleutnant Heinrich Schuch as part of the 6th U-boat Flotilla.