Massachusetts is located in the northeastern US, and the 4th largest of the six New England states in the US. It is ranked 45th in size among the 50 states in the US with a total area of 8,284 sq mi (21,456 sq km), of which land comprises 7,824 sq mi (20,265 sq km) and inland water occupies 460 sq mi (1,191 sq km).

Massachusetts is surrounded by by Vermont and New Hampshire to the North; by the Atlantic Ocean to the East; by the Atlantic Ocean, Rhode Island and Connecticut on the South; and by New York to the West.

Martha's Vineyard (108 sq mi or 280 sq km) and Nantucket (57 sq mi or 148 sq km) islands lie south of the state's fishhook-shaped Cape Cod peninsula. The Elizabeth Islands, SW of Cape Cod and North West of Martha's Vineyard, consist of 16 small islands separating Buzzards Bay from Vineyard Sound. The state's geographic center is located in Worcester County, in the northern section of the city of Worcester and . Boston is the capital of Massachusetts.