Günther Hessler (14 June 1909 – 4 April 1968) was a Kriegsmarine Fregattenkapitän 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, of which 86,699 GRT was sunk on one patrol alone. He was the twenty-first overall most successful U-boat commanders of World War II by tonnage sunk. Hessler was a recipient of the Knight's Cross of the Iron Cross and was commissioned after the war to write the official account of the U-boat war by the British Ministry of Defence.