German submarine U-1273 was a Type VIIC/41 U-boat of Nazi Germany's Kriegsmarine during World War II.
She was ordered on 23 March 1942, and was laid down on 7 June 1943, at Bremer Vulkan-Vegesacker Werft, Bremen-Vegesack, as yard number 68. She was launched on 10 January 1944, and commissioned under the command of Leutnant zur See Karl-Heinz Voswinkel on 16 February 1944.
German Type VIIC/41 submarines were preceded by the heavier Type VIIC submarines. U-1273 had a displacement of 769 tonnes (757 long tons) when at the surface and 871 tonnes (857 long tons) while submerged. She had a total length of 67.10 m (220 ft 2 in), a pressure hull length of 50.50 m (165 ft 8 in), an overall beam of 6.20 m (20 ft 4 in), a height of 9.60 m (31 ft 6 in), and a draught of 4.74 m (15 ft 7 in). The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of 2,800 to 3,200 metric horsepower (2,060 to 2,350 kW; 2,760 to 3,160 shp) for use while surfaced, two AEG GU 460/8-276 double-acting electric motors producing a total of 750 metric horsepower (550 kW; 740 shp) for use while submerged. She had two shafts and two 1.23 m (4 ft) propellers. The boat was capable of operating at depths of up to 230 metres (750 ft).The submarine had a maximum surface speed of 17.7 knots (32.8 km/h; 20.4 mph) and a maximum submerged speed of 7.6 knots (14.1 km/h; 8.7 mph). When submerged, the boat could operate for 80 nautical miles (150 km; 92 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 8,500 nautical miles (15,700 km; 9,800 mi) at 10 knots (19 km/h; 12 mph). U-1273 was fitted with five 53.3 cm (21 in) torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one 8.8 cm (3.46 in) SK C/35 naval gun, (220 rounds), one 3.7 cm (1.5 in) Flak M42 and two 2 cm (0.79 in) C/30 anti-aircraft guns. The boat had a complement of between forty-four and fifty-two.
On 17 February 1945, U-1273 struck a British air-laid mine off Horten in the Skagerrak in Oslofjord. Kapitänleutnant Helmut Knollmann and 42 other crewmen died out of a crew of 51.The wreck now lies at 59°24′N 10°32′E.