German submarine U-2345 was a Type XXIII U-boat of Nazi Germany's Kriegsmarine during World War II.

She was launched on 28 October 1944 and commissioned under the command of Oberleutnant zur See Karl Steffen on 15 November 1944.

The submarine was powered by one MWM six-cylinder RS134S diesel engine providing 575–630 metric horsepower (423–463 kilowatts; 567–621 shaft horsepower), one AEG GU4463-8 double-acting electric motor electric motor providing 580 PS (430 kW; 570 shp), and one BBC silent running CCR188 electric motor providing 35 PS (26 kW; 35 shp).

When submerged, the boat could operate at 4 knots (7.4 km/h; 4.6 mph) for 194 nautical miles (359 km; 223 mi); when surfaced, she could travel 2,600 nautical miles (4,800 km; 3,000 mi) at 8 knots (15 km/h; 9.2 mph).

Of the 156 U-boats that eventually surrendered to the Allied forces at the end of the war, U-2345 was one of 116 selected to take part in Operation Deadlight.