Middlesex County Demographics

A map of Middlesex County's Population by Race

Race	2024 Pop	2020 Pop	2024 %	2020 %
White	1,066,504	1,085,919	65.1%	66.5%
Asian	222,642	209,632	13.6%	12.8%
Hispanic	151,761	143,245	9.3%	8.8%
Multiracial	95,499	82,249	5.8%	5.0%
Black	77,245	80,996	4.7%	5.0%
Native American/Other	24,714	29,961	1.5%	1.8%

Middlesex County, Massachusetts has an estimated population of 1,638,365, a less than 1% change from the 1,632,002 recorded in the 2020 Census. The population is 65.1% White, 13.6% Asian, 9.3% Hispanic, 5.8% Multiracial, 4.7% Black, and 1.5% Native American/Other. This demographic dot map shows the population of Middlesex County, with one dot drawn for each person counted by the Census, color-coded by race.

Middlesex has become more racially diverse since the 2020 Census. It is more diverse than Massachusetts overall. Demographers use a diversity index to measure the probability that two randomly selected individuals belong to different racial or ethnic groups. In Middlesex County, that probability was 52.8% in 2020 and 54.3% in the most recent ACS estimates.

Middlesex County is ranked the most populous county in Massachusetts, out of 14 counties. Middlesex County was ranked the 1st most populous county in the 2020 Census.

Middlesex County's White Population

1,066,504 residents of Middlesex County, or 65.1% of the population, identify as White. The share of White residents in Middlesex County is comparable to the share in Massachusetts overall, where 66.6% of the population is White. Middlesex County ranks 11th statewide in terms of White residents as a share of the population, out of 14 counties.

Since the 2020 Census, Middlesex County's White population has declined by an estimated 1.8%. White residents' share of Middlesex County's population has decreased from 66.5% to 65.1%.

Middlesex County is more White than neighboring Suffolk County (43.6% White), and Essex County (64.5% White). Middlesex County is less White than neighboring Norfolk County (68.7% White), Worcester County (70.3% White), and Hillsborough County (80.1% White).

Middlesex County's Black Population

77,245 residents of Middlesex County, or 4.7% of the population, identify as Black. The share of Black residents in Middlesex County is comparable to the share in Massachusetts overall, where 6.4% of the population is Black. Middlesex County ranks 7th statewide in terms of Black residents as a share of the population, out of 14 counties.

Since the 2020 Census, Middlesex County's Black population has declined by an estimated 4.6%. Black residents' share of Middlesex County's population has remained roughly unchanged at 4.7%.

Middlesex County is more Black than neighboring Hillsborough County (2.2% Black), and Essex County (3.5% Black). Middlesex County is less Black than neighboring Norfolk County (7.1% Black), Suffolk County (17.1% Black), and Worcester County (4.8% Black).

Middlesex County's Asian Population

222,642 residents of Middlesex County, or 13.6% of the population, identify as Asian. The share of Asian residents in Middlesex County is higher than in Massachusetts overall, where 7.3% of the population is Asian. Middlesex County ranks 1st statewide in terms of Asian residents as a share of the population, out of 14 counties.

Since the 2020 Census, Middlesex County's Asian population has grown by an estimated 6.2%. Asian residents' share of Middlesex County's population has increased from 12.8% to 13.6%.

Middlesex County is more Asian than neighboring Norfolk County (12.4% Asian), Suffolk County (9.2% Asian), Worcester County (5.3% Asian), Hillsborough County (4.3% Asian), and Essex County (3.5% Asian).

Middlesex County's Hispanic Population

151,761 residents of Middlesex County, or 9.3% of the population, identify as Hispanic. The share of Hispanic residents in Middlesex County is slightly lower than in Massachusetts overall, where 13.3% of the population is Hispanic. Middlesex County ranks 7th statewide in terms of Hispanic residents as a share of the population, out of 14 counties.

Since the 2020 Census, Middlesex County's Hispanic population has grown by an estimated 5.9%. Hispanic residents' share of Middlesex County's population has increased from 8.8% to 9.3%.

Middlesex County is more Hispanic than neighboring Norfolk County (5.8% Hispanic), and Hillsborough County (8.5% Hispanic). Middlesex County is less Hispanic than neighboring Suffolk County (23.2% Hispanic), Worcester County (13.7% Hispanic), and Essex County (24.1% Hispanic).

Middlesex County's Native American/Other Population

24,714 residents of Middlesex County, or 1.5% of the population, identify as American Indian/Alaska Native/Native Hawaiian/Pacific Islander/Other. The share of Native American/Other residents in Middlesex County is comparable to the share in Massachusetts overall, where 1.3% of the population is Native American/Other. Middlesex County ranks 4th statewide in terms of Native American/Other residents as a share of the population, out of 14 counties.

Since the 2020 Census, Middlesex County's Native American/Other population has declined by an estimated 17.5%. Native American/Other residents' share of Middlesex County's population has remained roughly unchanged at 1.5%.

Middlesex County is more Native American/Other than neighboring Norfolk County (1.2% Native American/Other), Suffolk County (1.2% Native American/Other), Worcester County (1.2% Native American/Other), Hillsborough County (0.5% Native American/Other), and Essex County (0.9% Native American/Other).

Middlesex County's Multiracial Population

95,499 residents of Middlesex County, or 5.8% of the population, identify as Multiracial. The share of Multiracial residents in Middlesex County is comparable to the share in Massachusetts overall, where 5.1% of the population is Multiracial. Middlesex County ranks 5th statewide in terms of Multiracial residents as a share of the population, out of 14 counties.

Since the 2020 Census, Middlesex County's Multiracial population has grown by an estimated 16.1%. Multiracial residents' share of Middlesex County's population has increased from 5.0% to 5.8%.

Middlesex County is more Multiracial than neighboring Norfolk County (4.8% Multiracial), Suffolk County (5.6% Multiracial), Worcester County (4.7% Multiracial), Hillsborough County (4.3% Multiracial), and Essex County (3.5% Multiracial).

Sources: Most recent population estimates are from the 2020-2024 American Community Survey 5-Year Estimates. 2020 population counts and map data are from 2020 Census State Redistricting Data. Geographic data are from Census TIGER/Line Shapefiles.