Boston (pronounced Listeni/ˈbɒstən/) is the capital and largest city of the Commonwealth of Massachusetts in the United States. Boston also served as the historic county seat of Suffolk County until Massachusetts disbanded county government in 1999. The city proper covers 48 square miles (124 km2) with an estimated population of 655,884 in 2014, making it the largest city in New England and the 24th largest city in the United States. The city is the anchor of a substantially larger metropolitan area called Greater Boston, home to 4.5 million people and the tenth-largest metropolitan area in the country. Greater Boston as a commuting region is home to 7.6 million people, making it the sixth-largest Combined Statistical Area in the United States.

Boston's early European settlers had first called the area Trimountaine (after its "three mountains"—only traces of which remain today) but later renamed it Boston after Boston, Lincolnshire, England, from which several prominent colonists had come. The renaming, on September 7, 1630 (old style), was by Puritan colonists from England, who had moved over from Charlestown earlier that year in quest of fresh water. Their settlement was initially limited to the Shawmut Peninsula, at that time surrounded by the Massachusetts Bay and Charles River and connected to the mainland by a narrow isthmus. The peninsula is known to have been inhabited as early as 5000 BC.