Nantucket is an island in Massachusetts, United States, about 30 miles (48 km) south of the Cape Cod peninsula. Together with the small islands of Tuckernuck and Muskeget, it constitutes the Town and County of Nantucket, a combined county/town government. Nantucket is the southeasternmost town in Massachusetts. The name "Nantucket" is adapted from similar Algonquian names for the island.