Günter Hessler was a German naval officer during World War II. He commanded the Type IXB U-boat U-107, sinking twenty-one ships on three patrols, totalling 118,822 GRT of Allied shipping. Hessler was a recipient of the Knight's Cross of the Iron Cross and was commissioned after the war to write an account of the U-boat war by the British Ministry of Defence.

The Type IX U-boat was designed by Nazi Germany's Kriegsmarine in 1935 and 1936 as a large ocean-going submarine for sustained operations far from the home support facilities. Type IX boats were briefly used for patrols off the eastern United States in an attempt to disrupt the stream of troops and supplies bound for Europe. It was derived from the Type IA, and appeared in various sub-types.