默瑟湾是南极洲的海湾，位于南格鲁吉亚岛，是昆伯兰西湾的西南端，由瑞典探险队绘入地图，以英国海军的上尉指挥官命名。

Mercer Bay (54°16′S 36°40′W / 54.267°S 36.667°W / -54.267; -36.667) is a small bay marked by Geikie Glacier at its head, at the southwest end of Cumberland West Bay, South Georgia. The bay appears on a sketch map of Cumberland Bay by Lieutenant S.A. Duse of the Swedish Antarctic Expedition, 1901–04, and is first used on a chart based upon survey work by Discovery Investigations (DI) personnel in 1926–30. It was probably named for Lieutenant Commander G.M. Mercer, Royal Naval Reserve, captain of the DI research ship William Scoresby, which engaged in whale marking and oceanographic work off South Georgia in 1926–27.