German submarine U-1170 was a Type VIIC/41 U-boat of Nazi Germany's Kriegsmarine during World War II.

She was launched on 14 October 1943, and commissioned under the command of Oberleutnant zur See Friedrich Justi on 1 March 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 SSW GU 343/38-8 double-acting electric motors producing a total of 750 metric horsepower (550 kW; 740 shp) for use while submerged.

The boat was capable of operating at depths of up to 230 metres (750 ft).

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).