Data / Rankings / Population / Counties in Massachusetts

Counties in Massachusetts by population

Middlesex County had the highest population of 14 counties in 2021, at 1.61 million. Nantucket County had the lowest, at 14,518. The median was 497,700 and the figure for Massachusetts was 7 million. Source: the U.S. Census Bureau.

Highest1,614,929Middlesex County
Lowest14,518Nantucket County
Median497,70014 counties
Massachusetts6,996,721History

All counties, 2021

CSVChart (SVG)

Middlesex CountyMiddlesex County: 1,614,929 persons1,614,929Worcester CountyWorcester County: 862,157 persons862,157Essex CountyEssex County: 807,387 persons807,387Suffolk CountySuffolk County: 777,600 persons777,600Norfolk CountyNorfolk County: 724,970 persons724,970Bristol CountyBristol County: 579,699 persons579,699Plymouth CountyPlymouth County: 532,772 persons532,772Hampden CountyHampden County: 462,628 persons462,628Barnstable CountyBarnstable County: 232,449 persons232,449Hampshire CountyHampshire County: 165,218 persons165,218Berkshire CountyBerkshire County: 130,225 persons130,225Franklin CountyFranklin County: 71,059 persons71,059Dukes CountyDukes County: 21,110 persons21,110Nantucket CountyNantucket County: 14,518 persons14,518
persons. Source: U.S. Census Bureau. Retrieved 2026-10-08.

Full ranking

RankCounties2021
persons		Change on 2020
1Middlesex County1,614,929-0.6%
2Worcester County862,157+0.6%
3Essex County807,387-0.1%
4Suffolk County777,600-1.7%
5Norfolk County724,970+0.2%
6Bristol County579,699+0.5%
7Plymouth County532,772+0.8%
8Hampden County462,628-0.2%
9Barnstable County232,449+1.9%
10Hampshire County165,218+11.2%
11Berkshire County130,225+0.3%
12Franklin County71,059+0.2%
13Dukes County21,110+2.6%
14Nantucket County14,518+2%

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.

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Questions

Which county has the highest population?

Middlesex County, with 1.61 million in 2021, according to the U.S. Census Bureau.

Which county has the lowest population?

Nantucket County, with 14,518 in 2021.

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