German submarine U-636

German submarine U-636 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 2 October 1941 by Blohm & Voss, Hamburg as yard number 612, launched on 25 June 1942 and commissioned on 20 August 1942 under Oberleutnant zur See Hans Hildebrandt.

Service History
The boat's career began with training at 5th U-boat Flotilla on 20 August 1942, followed by active service on 1 April 1943 as part of the 11th Flotilla, operating from Bergen, Norway. Just six months later, she transferred to 13th Flotilla stationed in Trondheim, Norway, for the remainder of her service.

In 15 patrols she sank one merchant ship, for a total of.

Wolfpacks
U-636 took part in eleven wolfpacks, namely
 * Iller (12-15 May 1943)
 * Donau 1 (15-26 May 1943)
 * Isegrim (1-7 January 1944)
 * Donner (11-20 April 1944)
 * Donner & Keil (20 April - 2 May 1944)
 * Trutz (28 June - 10 July 1944)
 * Dachs (1-5 September 1944)
 * Zorn (26 September - 1 October 1944)
 * Grimm (1-2 October 1944)
 * Panther (16 October - 10 November 1944)
 * Stier (4-15 December 1944)

Fate
U-636 was sunk on 21 April 1945 in the North Atlantic in position 55.83333°N, -10.51667°W, by depth charges from HMS Bazely (K311), HMS Drury (K316) and HMS Bentinck (K314). All hands were lost.