St. Charles County, Missouri: Realigning Affluent Suburb county. In 2024, voted R+17%. Republican peak: R+46 in 1984.
Key facts
- 2024 presidential margin
- R+17MIT Election Lab
- Political typology
- Realigning Affluent SuburbAkashic typology
- Population
- 414,5352024 5-year
- Median household income
- $104,6922024 5-year
- White (non-Hispanic)
- 84.0%2024 5-year
- Black
- 5.1%2024 5-year
- Hispanic / Latino
- 4.2%2024 5-year
- Peak Democratic margin
- D+30 in 1932MIT Election Lab
- Peak Republican margin
- R+46 in 1984MIT Election Lab
- Most similar
- Clarke County, VA · similarity 0.99
2024 results by precinct
2024 precinct map of St. Charles CountyPrecinct-level 2024 presidential results for St. Charles County, with each precinct boundary colored by Democratic-vs-Republican margin.
—
Margin—
Turnout—
Harris +50Trump +50
Real precinct boundaries. Hover for vote totals.
presidential history
Presidential margin, 1876–2024
Democratic minus Republican, by election
| Year | Margin (D minus R) |
|---|---|
| 1876 | No data |
| 1880 | No data |
| 1884 | No data |
| 1888 | No data |
| 1892 | −0.7% |
| 1896 | −12.8% |
| 1900 | −17.1% |
| 1904 | −27.8% |
| 1908 | −27.1% |
| 1912 | −11.6% |
| 1916 | −29.3% |
| 1920 | −45.3% |
| 1924 | −29.2% |
| 1928 | −3.1% |
| 1932 | +30.2% |
| 1936 | +6.2% |
| 1940 | −18.7% |
| 1944 | −18.1% |
| 1948 | +0.6% |
| 1952 | −13.1% |
| 1956 | −10.8% |
| 1960 | +4.4% |
| 1964 | +23.4% |
| 1968 | −10.7% |
| 1972 | −39.9% |
| 1976 | −8.3% |
| 1980 | −25.7% |
| 1984 | −46.1% |
| 1988 | −26.1% |
| 1992 | −1.3% |
| 1996 | −6.2% |
| 2000 | −14.2% |
| 2004 | −17.7% |
| 2008 | −9.7% |
| 2012 | −20.9% |
| 2016 | −26.1% |
| 2020 | −17.5% |
| 2024 | −16.9% |
DemocraticRepublican
38 presidential elections
| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| R | 92,226 | 130,588 | 227,408 | ||
| R | 89,530 | 128,389 | 222,566 | ||
| R | 68,626 | 121,650 | 203,184 | ||
| R | 71,838 | 110,784 | 186,366 | ||
| R | 84,183 | 102,550 | 188,529 | ||
| R | 66,855 | 95,826 | 163,488 | ||
| R | 53,806 | 72,114 | 128,686 | ||
| R | 41,369 | 47,705 | 102,246 | ||
| R | 37,263 | 38,673 | 106,563 | ||
| R | 29,286 | 50,005 | 79,500 | ||
| R | 17,617 | 47,784 | 65,401 | ||
| R | 20,668 | 36,050 | 59,768 | ||
| R | 22,063 | 26,105 | 48,704 | ||
| R | 11,034 | 25,677 | 36,711 | ||
| R | 10,374 | 13,533 | 29,659 | ||
| D | 14,530 | 9,020 | 23,550 | ||
| D | 11,890 | 10,888 | 22,778 | ||
| R | 7,618 | 9,462 | 17,080 | ||
| R | 6,493 | 8,451 | 14,964 | ||
| D | 6,049 | 5,976 | 12,064 | ||
| R | 4,880 | 7,050 | 11,966 | ||
| R | 5,334 | 7,792 | 13,176 | ||
| D | 5,903 | 5,156 | 12,068 | ||
| D | 6,911 | 3,664 | 10,737 | ||
| R | 5,081 | 5,404 | 10,507 | ||
| R | 2,364 | 4,668 | 7,897 | ||
| R | 2,472 | 6,645 | 9,213 | ||
| R | 1,914 | 3,518 | 5,483 | ||
| R | 1,792 | 2,350 | 4,796 | ||
| R | 1,979 | 3,480 | 5,538 | ||
| R | 1,788 | 3,203 | 5,091 | ||
| R | 2,343 | 3,324 | 5,721 | ||
| R | 2,448 | 3,173 | 5,651 | ||
| R | 2,485 | 2,522 | 5,044 | ||
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Demographics
2024 ACS
Race, ethnicity, and ancestry
Click any group to see the ancestries typically reported within it.
German
31.3%
Irish
16.1%
English
12.6%
Italian
5.8%
American
5.8%
French
3.3%
Polish
2.9%
African American
4.1%
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. Hispanic/Latino is an ethnicity that overlaps the race categories, so these shares can total more than 100%. Ancestry is a self-reported, multiple-response item; ancestry percentages do not sum to the parent race percentage.
2024 ACS
Age distribution by sex
Median age: 39.8 in this county, 39.1 nationally
Male
Age
Female
85+
75–84
65–74
55–64
45–54
35–44
25–34
18–24
5–17
<5
Source · American Community Survey 5-year estimates, 2024 release.
2024 ACS
Median household income
Inflation-adjusted dollars
$104,692
St. Charles County ranks in the top 5% of US counties.
St. Charles County$104,692
Missouri$70,702
United States$80,734
St. Charles County ranks in the top 5% of US counties by median household income.
Source · American Community Survey 5-year estimates, 2024 release.
2024 ACS
Poverty rate
All persons below federal poverty line
5.2%
Child poverty is below the national average.
Children under 185.7%
Working age (18–64)4.9%
Seniors (65+)7.0%
Source · American Community Survey 5-year estimates, 2024 release.
2024 ACS
Language at home
Population aged 5 and older
94.2%
speak English only
Spanish2.1%
Asian & Pacific Islander1.7%
Other Indo-European1.6%
Other languages0.4%
Source · ACS 5-year estimates, 2024.
2020 religion census
Religious adherents
Adherents per capita by tradition
Source · 2020 US Religion Census. Remaining 50.4% of residents not counted as adherents by any reporting body.
St. Charles County has been one of Missouri's fastest-growing counties for two decades, fueled by suburban expansion from St. Louis. That population surge has not softened its Republican lean, which held at R+17 in 2024.
Once reliably Republican — a margin of forty-six points in 1984 at its widest — St. Charles County has trended Democratic. Between 2020 and 2024 the county moved one point toward the Democratic candidate; the 2024 margin was seventeen points.
A median household income of $104,692 — among the higher at this geographic scale — and a population of 414,535 describe the county. The county's voting pattern over the last decade is most similar to that of Clarke County and Antrim County.
Most similar counties
Compare two places, side by side
Twelve curated comparisons line up election history, demographics, and the divergence story for two places at a glance. Browse all comparisons →
Cite this page
All citations released under CC BY 4.0. Attribution: Akashic Intelligence.
St. Charles County, Missouri. Akashic. https://akashic.app/county/29183/. Accessed May 20, 2026. License: CC BY 4.0.
License: CC BY 4.0
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Frequently asked questions
How did St. Charles County, Missouri vote in 2024?
In 2024, St. Charles County, Missouri voted Republican by 16.9 points (R+17), carried by the Republican candidate. Out of 227,408 votes cast, 92,226 went Democratic and 130,588 went Republican.
What is St. Charles County, Missouri's political typology?
Akashic places St. Charles County, Missouri in the "Realigning Affluent Suburb" typology — College-educated, affluent suburbs — the one bloc moving toward the Democratic Party. The typology is a data-driven cluster built from vote share, vote swing, race and ethnicity, income, language spoken at home, religion, and ancestry. Across 38 elections in the dataset, the county has voted Democratic 5 times, Republican 29 times, and other 0 times.
When did St. Charles County, Missouri last vote Democratic?
The most recent presidential election in which St. Charles County, Missouri voted Democratic was 1964.
How many people live in St. Charles County, Missouri?
St. Charles County, Missouri has a population of 414,535 according to the 2024 American Community Survey 5-year estimates from the US Census Bureau.
What is the median household income in St. Charles County, Missouri?
Median household income in St. Charles County, Missouri is $104,692 — above the national median of $80,734. The Missouri state median is $70,702.
What is the political history of St. Charles County, Missouri?
Akashic tracks 38 presidential elections in St. Charles County, Missouri from 1876 to 2024. Of those, 5 went Democratic and 29 went Republican. The county's typology — "Realigning Affluent Suburb" — captures where that record, its demographics, and its recent swing place it among American communities.