Jefferson County Demographics

A map of Jefferson County's Population by Race

Race	2024 Pop	2020 Pop	2024 %	2020 %
White	202,967	203,287	88.5%	89.7%
Multiracial	14,801	12,456	6.5%	5.5%
Hispanic	6,066	5,552	2.6%	2.4%
Black	2,315	2,295	1.0%	1.0%
Asian	2,305	1,839	1.0%	0.8%
Native American/Other	1,004	1,310	0.4%	0.6%

Jefferson County, Missouri has an estimated population of 229,458, a slight increase from the 226,739 recorded in the 2020 Census. The population is 88.5% White, 6.5% Multiracial, 2.6% Hispanic, 1.0% Black, 1.0% Asian, and 0.4% 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 more racially diverse since the 2020 Census. It is considerably less diverse than Missouri 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 19.2% in 2020 and 21.3% in the most recent ACS estimates.

Jefferson County is ranked the 7th most populous county in Missouri, out of 115 counties. Jefferson County was ranked the 7th most populous county in the 2020 Census.

Jefferson County's White Population

202,967 residents of Jefferson County, or 88.5% of the population, identify as White. The share of White residents in Jefferson County is considerably higher than in Missouri overall, where 76.3% of the population is White. Jefferson County ranks 69th statewide in terms of White residents as a share of the population, out of 115 counties.

Since the 2020 Census, Jefferson County's White population has remained roughly the same. White residents' share of Jefferson County's population has decreased from 89.7% to 88.5%.

Jefferson County is more White than neighboring St. Louis County (61.4% White), and St. Louis County (44.4% White). Jefferson County is less White than neighboring Monroe County (95% White), Washington County (91.8% White), and St. Francois County (89.9% White).

Jefferson County's Black Population

2,315 residents of Jefferson County, or 1.0% of the population, identify as Black. The share of Black residents in Jefferson County is lower than in Missouri overall, where 10.9% of the population is Black. Jefferson County ranks 55th statewide in terms of Black residents as a share of the population, out of 115 counties.

Since the 2020 Census, Jefferson County's Black population has remained roughly the same. Black residents' share of Jefferson County's population has remained roughly unchanged at 1.0%.

Jefferson County is more Black than neighboring Monroe County (0.6% Black). Jefferson County is less Black than neighboring St. Louis County (24% Black), Washington County (1.7% Black), St. Francois County (2.7% Black), and St. Louis County (42.1% Black).

Jefferson County's Asian Population

2,305 residents of Jefferson County, or 1.0% of the population, identify as Asian. The share of Asian residents in Jefferson County is comparable to the share in Missouri overall, where 2.1% of the population is Asian. Jefferson County ranks 22nd statewide in terms of Asian residents as a share of the population, out of 115 counties.

Since the 2020 Census, Jefferson County's Asian population has grown by an estimated 25.3%. Asian residents' share of Jefferson County's population has remained roughly unchanged at 1.0%.

Jefferson County is more Asian than neighboring Monroe County (0.6% Asian), Washington County (0.1% Asian), and St. Francois County (0.4% Asian). Jefferson County is less Asian than neighboring St. Louis County (4.9% Asian), and St. Louis County (3.5% Asian).

Jefferson County's Hispanic Population

6,066 residents of Jefferson County, or 2.6% of the population, identify as Hispanic. The share of Hispanic residents in Jefferson County is slightly lower than in Missouri overall, where 5.2% of the population is Hispanic. Jefferson County ranks 45th statewide in terms of Hispanic residents as a share of the population, out of 115 counties.

Since the 2020 Census, Jefferson County's Hispanic population has grown by an estimated 9.3%. Hispanic residents' share of Jefferson County's population has remained roughly unchanged at 2.6%.

Jefferson County is more Hispanic than neighboring Monroe County (1.9% Hispanic), Washington County (1.1% Hispanic), and St. Francois County (1.9% Hispanic). Jefferson County is less Hispanic than neighboring St. Louis County (3.9% Hispanic), and St. Louis County (5.3% Hispanic).

Jefferson County's Native American/Other Population

1,004 residents of Jefferson County, or 0.4% 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 Missouri overall, where 0.7% of the population is Native American/Other. Jefferson County ranks 71st statewide in terms of Native American/Other residents as a share of the population, out of 115 counties.

Since the 2020 Census, Jefferson County's Native American/Other population has declined by an estimated 23.4%. Native American/Other residents' share of Jefferson County's population has remained roughly unchanged at 0.4%.

Jefferson County is more Native American/Other than neighboring Monroe County (0.2% Native American/Other), and Washington County (0.1% Native American/Other). Jefferson County is less Native American/Other than neighboring St. Louis County (0.6% Native American/Other), St. Francois County (1% Native American/Other), and St. Louis County (0.6% Native American/Other).

Jefferson County's Multiracial Population

14,801 residents of Jefferson County, or 6.5% of the population, identify as Multiracial. The share of Multiracial residents in Jefferson County is comparable to the share in Missouri overall, where 4.8% of the population is Multiracial. Jefferson County ranks 17th statewide in terms of Multiracial residents as a share of the population, out of 115 counties.

Since the 2020 Census, Jefferson County's Multiracial population has grown by an estimated 18.8%. Multiracial residents' share of Jefferson County's population has increased from 5.5% to 6.5%.

Jefferson County is more Multiracial than neighboring Monroe County (1.6% Multiracial), St. Louis County (5.3% Multiracial), Washington County (5.2% Multiracial), St. Francois County (4.1% Multiracial), and St. Louis County (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.