German submarine U-555 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. The submarine was laid down on 2 January 1940 at the Blohm & Voss yard in Hamburg as yard number 531, launched on 7 December 1940, and commissioned on 30 January 1941 under the command of Kapitänleutnant Hans-Joachim Horrer.
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-555 had a displacement of 769t when at the surface and 871t while submerged. She had a total length of 67.1m (220.1feet), a pressure hull length of 50.5m (165.7feet), a beam of 6.2m (20.3feet), a height of 9.6m (31.5feet), and a draught of 4.74m (15.55feet). The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of NaNPS for use while surfaced, two BBC GG UB 720/8 double-acting electric motors producing a total of 750PS for use while submerged. She had two shafts and two 1.23abbr=onNaNabbr=on 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-555 was fitted with two 53.30NaN0 torpedo tubes at the bow, fourteen torpedoes, one 8.82NaN2 SK C/35 naval gun, 220 rounds, and a 2sp=usNaNsp=us C/30 anti-aircraft gun. The boat had a complement of between forty-four and sixty.
Initially attached to the 24th U-boat Flotilla, she was transferred to the 21st U-boat Flotilla based at Pillau (now Baltiysk, Russia) on 1 December 1942, and served throughout the war under a number of commanders as a training boat, seeing no combat service.
The U-boat was stricken in March 1945, and surrendered to the British on 3 May 1945. She was later broken up in 1946.