Mawson Sea is an area of the sea along the Queen Mary Land coast of East Antarctica between the Shackleton Ice Shelf in the west and Vincennes Bay in the east. West of it, on the western side of Shackleton Ice Shelf, is the Davis Sea. To the east is Bowman Island and Vincennes Bay.
Two important glaciers debouche into the Mawson Sea: Scott Glacier and Denman Glacier. Calving of Denman Glacier into the Mawson Sea gives rise to the periodically appearing Pobeda Ice Island.
It was named in honor of Australian Antarctic explorer Douglas Mawson.
Coordinates: 65°00′S 105°00′E / 65.000°S 105.000°E