The list of shipwrecks in December 1939 includes ships sunk, foundered, grounded, or otherwise lost during December 1939.
For the loss of MV Realf on this day, see the entry for 30 November 1939 World War II: Battle of the River Plate: The Deutschland-class cruiser (12,340/16,020 t, 1936) was scuttled off Montevideo, Uruguay rather than engage with the Allies or be interned.