German submarine U-1278 was a Type VIIC/41 U-boat of Nazi Germany's Kriegsmarine during World War II.

She was ordered on 13 June 1942, and was laid down on 12 August 1943, at Bremer Vulkan AG, Bremen, as yard number 73.

She was launched on 15 April 1944, and commissioned under the command of Oberleutnant zur See Erich Müller-Bethke on 31 May 1944.

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.

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).