The most populous and capitol city in the Commonwealth of Massachusetts in the United States is Boston. The city is the financial and cultural hub of the Northeastern United States’ New England area. With a population of 675,647 as of the 2020 census, it is the third-largest city in the Northeast after New York City and Philadelphia. Its size is 48.4 sq mi (125 km2)]. With 4,919,179 residents as of 2023, the Greater Boston metropolitan statistical area—which encompasses the city and its surrounding areas—is the largest in New England and the eighth largest in the United States.