German submarine U-611 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 22 April 1941 by Blohm & Voss, Hamburg as yard number 587, launched on 8 January 1942 and commissioned on 26 February 1942 under Kapitänleutnant Nikolaus von Jacobs.
The boat's career began with training at 5th U-boat Flotilla on 26 February 1942, followed by active service on 1 October 1942 as part of the 3rd Flotilla for the remainder of her service. In one patrol she sank no ships.
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-611 had a displacement of when at the surface and while submerged. She had a total length of , a pressure hull length of , a beam of , a height of , and a draught of . The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of for use while surfaced, two BBC GG UB 720/8 double-acting electric motors producing a total of for use while submerged. She had two shafts and two propellers. The boat was capable of operating at depths of up to .
The submarine had a maximum surface speed of and a maximum submerged speed of . When submerged, the boat could operate for at ; when surfaced, she could travel at . U-611 was fitted with five torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one SK C/35 naval gun, 220 rounds, and a C/30 anti-aircraft gun. The boat had a complement of between forty-four and sixty.
U-611 took part in three wolfpacks, namely:
U-611 was sunk on 8 December 1942 in the North Atlantic SE of Cape Farewell, Greenland, in position , by depth charges from a RAF Liberator bomber of 120 Squadron. All hands were lost.