Jefferson County Demographics

A map of Jefferson County's Population by Race

Race	2024 Pop	2020 Pop	2024 %	2020 %
White	74,788	73,325	87.0%	86.4%
Hispanic	7,309	7,068	8.5%	8.3%
Multiracial	2,294	2,570	2.7%	3.0%
Black	793	864	0.9%	1.0%
Asian	533	646	0.6%	0.8%
Native American/Other	286	427	0.3%	0.5%

Jefferson County, Wisconsin has an estimated population of 86,003, a slight increase from the 84,900 recorded in the 2020 Census. The population is 87.0% White, 8.5% Hispanic, 2.7% Multiracial, 0.9% Black, 0.6% Asian, and 0.3% Native American/Other. This demographic dot map shows the population of Jefferson County, with one dot drawn for each person counted by the Census, color-coded by race.

Jefferson has become less racially diverse since the 2020 Census. It is considerably less diverse than Wisconsin overall. Demographers use a diversity index to measure the probability that two randomly selected individuals belong to different racial or ethnic groups. In Jefferson County, that probability was 24.6% in 2020 and 23.6% in the most recent ACS estimates.

Jefferson County is ranked the 20th most populous county in Wisconsin, out of 72 counties. Jefferson County was ranked the 20th most populous county in the 2020 Census.

Jefferson County's White Population

74,788 residents of Jefferson County, or 87.0% of the population, identify as White. The share of White residents in Jefferson County is higher than in Wisconsin overall, where 78.6% of the population is White. Jefferson County ranks 51st statewide in terms of White residents as a share of the population, out of 72 counties.

Since the 2020 Census, Jefferson County's White population has grown by an estimated 2.0%. White residents' share of Jefferson County's population has increased from 86.4% to 87.0%.

Jefferson County is more White than neighboring Walworth County (83.1% White), Rock County (79.6% White), Waukesha County (85% White), and Dane County (75.8% White). Jefferson County is less White than neighboring Dodge County (87.3% White).

Jefferson County's Black Population

793 residents of Jefferson County, or 0.9% of the population, identify as Black. The share of Black residents in Jefferson County is slightly lower than in Wisconsin overall, where 5.9% of the population is Black. Jefferson County ranks 31st statewide in terms of Black residents as a share of the population, out of 72 counties.

Since the 2020 Census, Jefferson County's Black population has declined by an estimated 8.2%. Black residents' share of Jefferson County's population has remained roughly unchanged at 0.9%.

Jefferson County is more Black than neighboring Walworth County (0.7% Black). Jefferson County is less Black than neighboring Dodge County (2.5% Black), Rock County (4.6% Black), Waukesha County (1.5% Black), and Dane County (5.1% Black).

Jefferson County's Asian Population

533 residents of Jefferson County, or 0.6% of the population, identify as Asian. The share of Asian residents in Jefferson County is slightly lower than in Wisconsin overall, where 2.9% of the population is Asian. Jefferson County ranks 26th statewide in terms of Asian residents as a share of the population, out of 72 counties.

Since the 2020 Census, Jefferson County's Asian population has declined by an estimated 17.5%. Asian residents' share of Jefferson County's population has remained roughly unchanged at 0.6%.

Jefferson County is more Asian than neighboring Dodge County (0.5% Asian). Jefferson County is less Asian than neighboring Walworth County (0.8% Asian), Rock County (1.1% Asian), Waukesha County (3.9% Asian), and Dane County (6.1% Asian).

Jefferson County's Hispanic Population

7,309 residents of Jefferson County, or 8.5% of the population, identify as Hispanic. The share of Hispanic residents in Jefferson County is comparable to the share in Wisconsin overall, where 8% of the population is Hispanic. Jefferson County ranks 8th statewide in terms of Hispanic residents as a share of the population, out of 72 counties.

Since the 2020 Census, Jefferson County's Hispanic population has grown by an estimated 3.4%. Hispanic residents' share of Jefferson County's population has remained roughly unchanged at 8.5%.

Jefferson County is more Hispanic than neighboring Dodge County (6.7% Hispanic), Waukesha County (5.7% Hispanic), and Dane County (7.8% Hispanic). Jefferson County is less Hispanic than neighboring Walworth County (12.1% Hispanic), and Rock County (10.1% Hispanic).

Jefferson County's Native American/Other Population

286 residents of Jefferson County, or 0.3% of the population, identify as American Indian/Alaska Native/Native Hawaiian/Pacific Islander/Other. The share of Native American/Other residents in Jefferson County is comparable to the share in Wisconsin overall, where 0.9% of the population is Native American/Other. Jefferson County ranks 59th statewide in terms of Native American/Other residents as a share of the population, out of 72 counties.

Since the 2020 Census, Jefferson County's Native American/Other population has declined by an estimated 33.0%. Native American/Other residents' share of Jefferson County's population has remained roughly unchanged at 0.3%.

Jefferson County is less Native American/Other than neighboring Dodge County (0.5% Native American/Other), Walworth County (0.4% Native American/Other), Waukesha County (0.6% Native American/Other), and Dane County (0.6% Native American/Other).

Jefferson County's Multiracial Population

2,294 residents of Jefferson County, or 2.7% of the population, identify as Multiracial. The share of Multiracial residents in Jefferson County is comparable to the share in Wisconsin overall, where 3.7% of the population is Multiracial. Jefferson County ranks 37th statewide in terms of Multiracial residents as a share of the population, out of 72 counties.

Since the 2020 Census, Jefferson County's Multiracial population has declined by an estimated 10.7%. Multiracial residents' share of Jefferson County's population has remained roughly unchanged at 2.7%.

Jefferson County is more Multiracial than neighboring Dodge County (2.5% Multiracial). Jefferson County is less Multiracial than neighboring Walworth County (2.8% Multiracial), Rock County (4.2% Multiracial), Waukesha County (3.2% Multiracial), and Dane County (4.6% 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.