Frenchman Bay (often spelled Frenchmans Bay) is a bay in Hancock County, Maine, named for Samuel de Champlain, the French explorer who visited the area in 1604.
The bay is bounded on the east by the Schoodic Peninsula, and on the west by Mount Desert Island; parts of both are in Acadia National Park. It contains numerous islands, the largest of which is Ironbound Island. The largest town on the bay is Bar Harbor, on Mt. Desert.
The bay extends for roughly 15 miles (24 km) and spans 7 miles (11 km) at its widest.
Coordinates: 44°24′51″N 68°11′06″W / 44.41417°N 68.18500°W