Middlesex County Demographics

A map of Middlesex County's Population by Race

Race	2024 Pop	2020 Pop	2024 %	2020 %
White	326,790	333,158	37.5%	38.6%
Asian	221,341	227,973	25.4%	26.4%
Hispanic	205,792	193,687	23.6%	22.4%
Black	84,565	78,719	9.7%	9.1%
Multiracial	25,330	21,197	2.9%	2.5%
Native American/Other	7,472	8,428	0.9%	1.0%

Middlesex County, New Jersey has an estimated population of 871,290, a less than 1% change from the 863,162 recorded in the 2020 Census. The population is 37.5% White, 25.4% Asian, 23.6% Hispanic, 9.7% Black, 2.9% Multiracial, and 0.9% 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 slightly more racially diverse since the 2020 Census. It is considerably more diverse than New Jersey 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 72.2% in 2020 and 72.9% in the most recent ACS estimates.

Middlesex County is ranked the 2nd most populous county in New Jersey, out of 21 counties. Middlesex County was ranked the 3rd most populous county in the 2020 Census.

Middlesex County's White Population

326,790 residents of Middlesex County, or 37.5% of the population, identify as White. The share of White residents in Middlesex County is considerably lower than in New Jersey overall, where 50.9% of the population is White. Middlesex County ranks 18th statewide in terms of White residents as a share of the population, out of 21 counties.

Since the 2020 Census, Middlesex County's White population has declined by an estimated 1.9%. White residents' share of Middlesex County's population has decreased from 38.6% to 37.5%.

Middlesex County is more White than neighboring Union County (35.4% White). Middlesex County is less White than neighboring Somerset County (49.3% White), Monmouth County (71.5% White), Richmond County (55.5% White), and Mercer County (42.7% White).

Middlesex County's Black Population

84,565 residents of Middlesex County, or 9.7% of the population, identify as Black. The share of Black residents in Middlesex County is slightly lower than in New Jersey overall, where 12.2% of the population is Black. Middlesex County ranks 12th statewide in terms of Black residents as a share of the population, out of 21 counties.

Since the 2020 Census, Middlesex County's Black population has grown by an estimated 7.4%. Black residents' share of Middlesex County's population has increased from 9.1% to 9.7%.

Middlesex County is more Black than neighboring Somerset County (9.3% Black), Monmouth County (5.8% Black), and Richmond County (8.8% Black). Middlesex County is less Black than neighboring Union County (19.1% Black), and Mercer County (17.9% Black).

Middlesex County's Asian Population

221,341 residents of Middlesex County, or 25.4% of the population, identify as Asian. The share of Asian residents in Middlesex County is significantly higher than in New Jersey overall, where 10% of the population is Asian. Middlesex County ranks 1st statewide in terms of Asian residents as a share of the population, out of 21 counties.

Since the 2020 Census, Middlesex County's Asian population has declined by an estimated 2.9%. Asian residents' share of Middlesex County's population has decreased from 26.4% to 25.4%.

Middlesex County is more Asian than neighboring Somerset County (19.6% Asian), Union County (5.6% Asian), Monmouth County (5.4% Asian), Richmond County (12.7% Asian), and Mercer County (12.3% Asian).

Middlesex County's Hispanic Population

205,792 residents of Middlesex County, or 23.6% of the population, identify as Hispanic. The share of Hispanic residents in Middlesex County is comparable to the share in New Jersey overall, where 22.5% of the population is Hispanic. Middlesex County ranks 6th statewide in terms of Hispanic residents as a share of the population, out of 21 counties.

Since the 2020 Census, Middlesex County's Hispanic population has grown by an estimated 6.2%. Hispanic residents' share of Middlesex County's population has increased from 22.4% to 23.6%.

Middlesex County is more Hispanic than neighboring Somerset County (17.6% Hispanic), Monmouth County (12.9% Hispanic), Richmond County (19.6% Hispanic), and Mercer County (23.1% Hispanic). Middlesex County is less Hispanic than neighboring Union County (35.2% Hispanic).

Middlesex County's Native American/Other Population

7,472 residents of Middlesex County, or 0.9% 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 New Jersey overall, where 0.9% of the population is Native American/Other. Middlesex County ranks 5th statewide in terms of Native American/Other residents as a share of the population, out of 21 counties.

Since the 2020 Census, Middlesex County's Native American/Other population has declined by an estimated 11.3%. Native American/Other residents' share of Middlesex County's population has remained roughly unchanged at 0.9%.

Middlesex County is more Native American/Other than neighboring Somerset County (0.7% Native American/Other), Richmond County (0.7% Native American/Other), and Mercer County (0.6% Native American/Other). Middlesex County is less Native American/Other than neighboring Union County (1.3% Native American/Other).

Middlesex County's Multiracial Population

25,330 residents of Middlesex County, or 2.9% of the population, identify as Multiracial. The share of Multiracial residents in Middlesex County is comparable to the share in New Jersey overall, where 3.5% of the population is Multiracial. Middlesex County ranks 20th statewide in terms of Multiracial residents as a share of the population, out of 21 counties.

Since the 2020 Census, Middlesex County's Multiracial population has grown by an estimated 19.5%. Multiracial residents' share of Middlesex County's population has remained roughly unchanged at 2.9%.

Middlesex County is more Multiracial than neighboring Richmond County (2.7% Multiracial). Middlesex County is less Multiracial than neighboring Somerset County (3.6% Multiracial), Union County (3.4% Multiracial), Monmouth County (3.6% Multiracial), and Mercer County (3.4% 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.