Button Island is a small island in the Hingham Bay area of the Boston Harbor Islands National Recreation Area. It is part of the Town of Hingham. The island has a permanent size of under 1-acre (4,000 m²), plus an intertidal zone of a further 116 acres (0.47 km²). It is composed of a massing of glacial till which rises to a height of 10 feet (3.0 m) above sea level.