| Günther Heydemann | |
| Birth Date: | 11 January 1914 |
| Birth Place: | Greifswald |
| Death Place: | Hamburg-Wedel |
| Serviceyears: | 1933–1945 |
| Rank: | Kapitänleutnant |
| Unit: | SSS Gorch Fock cruiser Karlsruhe |
| Battles: | Battle of the Atlantic |
| Awards: | Knight's Cross of the Iron Cross |
Günther Heydemann (11 January 1914 – 2 January 1986) was a German U-boat commander in the Kriegsmarine of Nazi Germany in World War II. He was a recipient of the Knight's Cross of the Iron Cross. Prior to taking command of, Heydemann made two war patrols as watch officer on board under the command of Kapitänleutnant Jost Metzler.
From 15 September to 2 October 1941, Heydemann, as commander of, was part of Wolfpack Brandenburg operating southeast of Greenland in the North Atlantic. On 2 October, Heydemann sank Tuva of . On U-575s third war patrol which was part of the second wave of Operation Drumbeat, also referred to as the Second Happy Time, Heydemann was given a special task and did not sink any ships. On U-575s fourth war patrol which was part of the fifth wave of Operation Drumbeat, Heydemann sank Robin Hood of on 16 April 1942.
As commander of Günther Heydmann is credited with the sinking of eight ships for a total of .
. . 2000 . 1986 . Die Träger des Ritterkreuzes des Eisernen Kreuzes 1939–1945 — Die Inhaber der höchsten Auszeichnung des Zweiten Weltkrieges aller Wehrmachtteile . The Bearers of the Knight's Cross of the Iron Cross 1939–1945 — The Owners of the Highest Award of the Second World War of all Wehrmacht Branches . German . Friedberg, Germany . Podzun-Pallas . 978-3-7909-0284-6.
de:Gerhard Hümmelchen
. 1968 . Chronik des Seekrieges 1939–45 . Chronicle of Naval Warfare 1939–45 . de . Herrsching, Germany . Pawlak . 978-3-88199-009-7.