German submarine U-1103 was a Type VIIC/41 U-boat of Nazi Germany's Kriegsmarine during World War II.

She was launched on 12 October 1943, and commissioned under the command of Kapitänleutnant Hans Bungards on 8 January 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.

[7] On 5 May 1945, U-1103 surrendered at Cuxhaven, Germany and was later transferred from Wilhelmshaven to Loch Ryan, Scotland.

Of the 156 U-boats that eventually surrendered to the Allied forces at the end of the war, U-1103 was one of 116 selected to take part in Operation Deadlight.