Hillsborough County Demographics

A map of Hillsborough County's Population by Race

Race	2024 Pop	2020 Pop	2024 %	2020 %
White	341,341	342,652	80.1%	81.0%
Hispanic	36,414	33,498	8.5%	7.9%
Multiracial	18,416	17,205	4.3%	4.1%
Asian	18,338	16,413	4.3%	3.9%
Black	9,550	10,044	2.2%	2.4%
Native American/Other	2,319	3,125	0.5%	0.7%

Hillsborough County, New Hampshire has an estimated population of 426,378, a less than 1% change from the 422,937 recorded in the 2020 Census. The population is 80.1% White, 8.5% Hispanic, 4.3% Asian, 4.3% Multiracial, 2.2% Black, and 0.5% Native American/Other. This demographic dot map shows the population of Hillsborough County, with one dot drawn for each person counted by the Census, color-coded by race.

Hillsborough has become more racially diverse since the 2020 Census. It is considerably more diverse than New Hampshire overall. Demographers use a diversity index to measure the probability that two randomly selected individuals belong to different racial or ethnic groups. In Hillsborough County, that probability was 33.4% in 2020 and 34.8% in the most recent ACS estimates.

Hillsborough County is ranked the most populous county in New Hampshire, out of 10 counties. Hillsborough County was ranked the 1st most populous county in the 2020 Census.

Hillsborough County's White Population

341,341 residents of Hillsborough County, or 80.1% of the population, identify as White. The share of White residents in Hillsborough County is lower than in New Hampshire overall, where 86.9% of the population is White. Hillsborough County ranks 10th statewide in terms of White residents as a share of the population, out of 10 counties.

Since the 2020 Census, Hillsborough County's White population has remained roughly the same. White residents' share of Hillsborough County's population has decreased from 81.0% to 80.1%.

Hillsborough County is more White than neighboring Middlesex County (65.1% White), and Worcester County (70.3% White). Hillsborough County is less White than neighboring Merrimack County (90.1% White), Cheshire County (91.4% White), and Rockingham County (89.5% White).

Hillsborough County's Black Population

9,550 residents of Hillsborough County, or 2.2% of the population, identify as Black. The share of Black residents in Hillsborough County is comparable to the share in New Hampshire overall, where 1.3% of the population is Black. Hillsborough County ranks 1st statewide in terms of Black residents as a share of the population, out of 10 counties.

Since the 2020 Census, Hillsborough County's Black population has declined by an estimated 4.9%. Black residents' share of Hillsborough County's population has remained roughly unchanged at 2.2%.

Hillsborough County is more Black than neighboring Merrimack County (1.6% Black), Cheshire County (0.7% Black), and Rockingham County (0.7% Black). Hillsborough County is less Black than neighboring Middlesex County (4.7% Black), and Worcester County (4.8% Black).

Hillsborough County's Asian Population

18,338 residents of Hillsborough County, or 4.3% of the population, identify as Asian. The share of Asian residents in Hillsborough County is comparable to the share in New Hampshire overall, where 2.6% of the population is Asian. Hillsborough County ranks 1st statewide in terms of Asian residents as a share of the population, out of 10 counties.

Since the 2020 Census, Hillsborough County's Asian population has grown by an estimated 11.7%. Asian residents' share of Hillsborough County's population has remained roughly unchanged at 4.3%.

Hillsborough County is more Asian than neighboring Merrimack County (1.5% Asian), Cheshire County (0.9% Asian), and Rockingham County (1.9% Asian). Hillsborough County is less Asian than neighboring Middlesex County (13.6% Asian), and Worcester County (5.3% Asian).

Hillsborough County's Hispanic Population

36,414 residents of Hillsborough County, or 8.5% of the population, identify as Hispanic. The share of Hispanic residents in Hillsborough County is slightly higher than in New Hampshire overall, where 4.7% of the population is Hispanic. Hillsborough County ranks 1st statewide in terms of Hispanic residents as a share of the population, out of 10 counties.

Since the 2020 Census, Hillsborough County's Hispanic population has grown by an estimated 8.7%. Hispanic residents' share of Hillsborough County's population has increased from 7.9% to 8.5%.

Hillsborough County is more Hispanic than neighboring Merrimack County (2.7% Hispanic), Cheshire County (2.6% Hispanic), and Rockingham County (3.7% Hispanic). Hillsborough County is less Hispanic than neighboring Middlesex County (9.3% Hispanic), and Worcester County (13.7% Hispanic).

Hillsborough County's Native American/Other Population

2,319 residents of Hillsborough County, or 0.5% of the population, identify as American Indian/Alaska Native/Native Hawaiian/Pacific Islander/Other. The share of Native American/Other residents in Hillsborough County is comparable to the share in New Hampshire overall, where 0.5% of the population is Native American/Other. Hillsborough County ranks 2nd statewide in terms of Native American/Other residents as a share of the population, out of 10 counties.

Since the 2020 Census, Hillsborough County's Native American/Other population has declined by an estimated 25.8%. Native American/Other residents' share of Hillsborough County's population has remained roughly unchanged at 0.5%.

Hillsborough County is more Native American/Other than neighboring Cheshire County (0.3% Native American/Other). Hillsborough County is less Native American/Other than neighboring Middlesex County (1.5% Native American/Other), Worcester County (1.2% Native American/Other), and Rockingham County (0.6% Native American/Other).

Hillsborough County's Multiracial Population

18,416 residents of Hillsborough County, or 4.3% of the population, identify as Multiracial. The share of Multiracial residents in Hillsborough County is comparable to the share in New Hampshire overall, where 4% of the population is Multiracial. Hillsborough County ranks 5th statewide in terms of Multiracial residents as a share of the population, out of 10 counties.

Since the 2020 Census, Hillsborough County's Multiracial population has grown by an estimated 7.0%. Multiracial residents' share of Hillsborough County's population has remained roughly unchanged at 4.3%.

Hillsborough County is more Multiracial than neighboring Merrimack County (3.6% Multiracial), Cheshire County (4.1% Multiracial), and Rockingham County (3.6% Multiracial). Hillsborough County is less Multiracial than neighboring Middlesex County (5.8% Multiracial), and Worcester County (4.7% 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.