Dorchester Bay (Boston Harbor)

View to the northwest of Quincy toward Boston via the Dorchester Bay

The Dorchester Bay is the smallest of the three bays in the southern part of Boston Harbor and Massachusetts Bay in the state of Massachusetts in the United States. The bay forms the southern part of the coast line of the Boston district of South Boston, the north-eastern coast of Dorchester and the northern coastline of the city of Quincy.

In the bay is Thompson Iceland, one of the harbor islands in Boston Harbor. The Neponset River flows between Dorchester and Squantum Point Park in Quincy in the Dorchester Bay. On the west coast of the bay at the end of the Columbia Point peninsula, the John F. Kennedy Library and Museum. Along the northern coast extends for 2.6 mi (4 km ) of the Day Boulevard, one of the Parkways of the Massachusetts Department of Conservation and Recreation and part of the Metropolitan Park System of Greater Boston.