Data / Rankings / Population / Counties in Massachusetts

Counties in Massachusetts by population

Middlesex County had the highest population of 14 counties in 2020, at 1.62 million. Nantucket County had the lowest, at 14,240. The median was 496,032 and the figure for Massachusetts was 6.99 million. Source: the U.S. Census Bureau.

Highest1,624,461Middlesex County
Lowest14,240Nantucket County
Median496,03214 counties
Massachusetts6,985,320History

All counties, 2020

CSVChart (SVG)

Middlesex CountyMiddlesex County: 1,624,461 persons1,624,461Worcester CountyWorcester County: 857,028 persons857,028Essex CountyEssex County: 807,799 persons807,799Suffolk CountySuffolk County: 791,372 persons791,372Norfolk CountyNorfolk County: 723,647 persons723,647Bristol CountyBristol County: 576,723 persons576,723Plymouth CountyPlymouth County: 528,413 persons528,413Hampden CountyHampden County: 463,651 persons463,651Barnstable CountyBarnstable County: 228,055 persons228,055Hampshire CountyHampshire County: 148,597 persons148,597Berkshire CountyBerkshire County: 129,816 persons129,816Franklin CountyFranklin County: 70,938 persons70,938Dukes CountyDukes County: 20,580 persons20,580Nantucket CountyNantucket County: 14,240 persons14,240
persons. Source: U.S. Census Bureau. Retrieved 2026-10-08.

Full ranking

RankCounties2020
persons
1Middlesex County1,624,461
2Worcester County857,028
3Essex County807,799
4Suffolk County791,372
5Norfolk County723,647
6Bristol County576,723
7Plymouth County528,413
8Hampden County463,651
9Barnstable County228,055
10Hampshire County148,597
11Berkshire County129,816
12Franklin County70,938
13Dukes County20,580
14Nantucket County14,240

Other periods

About this ranking

Resident population. Spain and the EU: 1 January, with Spanish figures from the official municipal register (Padrón). United States: Census Bureau population estimates for 1 July. Other countries and the World: World Bank mid-year estimates, which count all residents regardless of legal status or citizenship.

For Denmark, Statistics Denmark counts the registered resident population on 1 January. Greenland and the Faroe Islands are excluded. The annual series selects the first-quarter reference date from FOLK1A. The World Bank series exists for every country, so use it (through compare) to rank countries on one basis.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. Equal values share a rank.

How to cite

U.S. Census Bureau. Annual estimates of the resident population for the United States, states and counties, 1 July (Population Estimates Program). https://www2.census.gov/programs-surveys/popest/datasets/2020-2025/. Retrieved 2026-10-08.

Use this data in your AI agent

Invokely serves this figure to AI assistants through MCP and to code through a REST API, with the source and citation attached. Ask your assistant:

Rank Counties in Massachusetts by population using official data, and cite the source.
rank_places {"indicator":"population","level":"province","within":"Massachusetts","limit":10}
GET https://invokely.ai/api/v1/rank?indicator=population&level=province&within=Massachusetts&limit=10

Connect Claude, ChatGPT or Cursor in one step. The trial answers 25 calls a day without an account.

Questions

Which county has the highest population?

Middlesex County, with 1.62 million in 2020, according to the U.S. Census Bureau.

Which county has the lowest population?

Nantucket County, with 14,240 in 2020.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: U.S. Census Bureau, Annual estimates of the resident population for the United States, states and counties, 1 July (Population Estimates Program). Retrieved 2026-10-08.

Population: other rankings

Counties in Massachusetts: more rankings