German submarine U-1209 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II.

She was ordered on 2 April 1942 and was laid down on 14 July 1943 at F Schichau GmbH, Danzig, as yard number 1579.

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.

[3] U-1209 was scuttled by her crew on 18 December 1944, east of the Isles of Scilly, in the English Channel, after running aground on Wolf Rock.

Forty-four of her crew of fifty-three survived, Oberleutnant zur See Ewald Hülsenbeck was among the dead.