Jefferson County, Missouri

2024 results by precinct

51 precincts · 119,833 votes cast

Trump · R+37

Harris +50

Trump +50

Real precinct boundaries. Hover for vote totals.

38 presidential elections

Year	Won	Margin	Democratic	Republican	Total
2024	R	−36.6%	36,965	80,796	119,833
2020	R	−33.4%	37,856	77,046	117,286
2016	R	−35.0%	31,568	69,036	106,995
2012	R	−12.7%	41,564	53,978	98,024
2008	D	+2.5%	53,467	50,804	105,704
2004	R	−0.6%	46,057	46,624	93,264
2000	D	+2.4%	38,616	36,766	77,204
1996	D	+12.4%	32,073	23,877	66,102
1992	D	+16.2%	32,569	20,637	73,501
1988	R	−2.7%	27,738	29,279	57,232
1984	R	−26.6%	20,026	34,525	54,551
1980	R	−8.2%	24,042	28,546	54,882
1976	D	+15.7%	25,159	18,261	43,915
1972	R	−22.8%	13,787	21,947	35,734
1968	D	+4.9%	13,230	11,708	31,053
1964	D	+41.1%	18,916	7,887	26,803
1960	D	+13.8%	17,054	12,910	29,964
1956	D	+12.8%	13,868	10,712	24,580
1952	D	+14.3%	12,808	9,607	22,437
1948	D	+25.5%	10,280	6,085	16,435
1944	D	+8.1%	7,953	6,758	14,745
1940	D	+11.9%	9,553	7,517	17,115
1936	D	+23.9%	9,158	5,575	14,974
1932	D	+27.8%	8,130	4,559	12,844
1928	R	−9.1%	5,231	6,285	11,538
1924	R	−5.2%	4,356	4,870	9,963
1920	R	−9.9%	4,684	5,730	10,595
1916	R	−4.5%	3,021	3,310	6,489
1912	D	+4.6%	2,368	2,127	5,208
1908	R	−6.0%	2,698	3,050	5,865
1904	R	−6.2%	2,560	2,909	5,585
1900	D	+0.4%	2,798	2,775	5,640
1896	R	−1.6%	2,785	2,876	5,699
1892	D	+8.3%	2,617	2,207	4,937
1888	—	No data	—	—	—
1884	—	No data	—	—	—
1880	—	No data	—	—	—
1876	—	No data	—	—	—

Demographics

Race, ethnicity, and ancestry

Click any group to see the ancestries typically reported within it.

American

100.0%

African American

0.8%

Multiple ancestry combinations reported; no single grouping above 1%.

American Indian, Alaska Native, Native Hawaiian, and Pacific Islander combined.

Source · American Community Survey 5-year estimates, 2024 release. Ancestry is a self-reported, multiple-response item; ancestry percentages do not sum to the parent race percentage.

Age distribution by sex

Median age: 40.3 in this county, 39.1 nationally

Male

Age

Female

0.7%

85+

0.9%

1.9%

75–84

2.5%

5.1%

65–74

5.5%

7.2%

55–64

7.3%

6.5%

45–54

6.3%

6.9%

35–44

6.8%

6.3%

25–34

6.1%

3.8%

18–24

3.6%

8.7%

5–17

8.3%

2.8%

2.7%

Source · American Community Survey 5-year estimates, 2024 release.

Median household income

2024 inflation-adjusted dollars

$82,851

Jefferson County ranks in the top 25% of US counties.

Jefferson County$82,851

Missouri$70,702

United States$80,734

Source · American Community Survey 5-year estimates, 2024 release.

Poverty rate

All persons below federal poverty line

9.0%

Children face moderate poverty.

Children under 1818.0%

Working age (18–64)100.0%

Seniors (65+)18.0%

Source · American Community Survey 5-year estimates, 2024 release.

Language at home

Population aged 5 and older

0.0%

speak English only

Source · ACS 5-year estimates, 2024.

Religious adherents

Adherents per capita by tradition

Catholic & Orthodox

14.7%

Baptist

11.0%

Other Christian

3.5%

Mainline Protestant

3.3%

Pentecostal & Holiness

1.7%

Methodist

0.9%

Source · 2020 US Religion Census. Remaining 64.9% of residents not counted as adherents by any reporting body.

Once a competitive swing county on St. Louis's southern fringe, Jefferson has moved decisively toward Republican presidential candidates since 2000, reflecting a broader realignment among working-class white voters in Missouri's outer suburbs.

The Republican margin in Jefferson County reached its widest at thirty-seven points in 2024. The margin in 2024 was thirty-seven points, in line with the county's deep historical pattern.

Jefferson County's loyalty is rooted in its place. Median household income of $82,851, a 89% non-Hispanic-white share, and a population of 229,458 together describe a community whose political habits are deeply settled. The county's voting pattern over the last decade is most similar to that of Washington County and St. Francois County.

Most similar counties

Jefferson County has voted Republican for as long as anyone can remember.