Grape Island is an island in the Hingham Bay area of the Boston Harbor Islands National Recreation Area. The island is part of the territory of the town of Weymouth, Massachusetts. The island has a permanent size of 54 acres (220,000 m2), plus an intertidal zone of a further 46 acres (190,000 m2), and is composed of two drumlins, reaching an elevation of 70 feet (21 m) above sea level, and connected by a marshy lowland. Tidal sand spits extend from the west end towards Weymouth Neck in Webb Memorial State Park and from the east end towards Slate Island.