St. Clair County, Missouri
Located in Missouri, St. Clair County has a population of 9,587 residents and a median age of 46.1 years, making it the #2,519 most populous county out of 3,222 nationwide. In terms of economic indicators, the county has a poverty rate of 14.7%. The median home value is $157,100, and the median household income is $53,043, which is 29% below the national median.
Demographics
St. Clair County has a population of 9,587, making it the #2,519 most populous county in the US. The median age is 46.1 years, which is 18.5% above the national median.
Population Trend
Rankings →Year-over-Year Population Growth
Age & Sex Distribution
Race & Ethnicity
Nativity
Geographic Mobility (Past Year)
Economy
The median household income in St. Clair County is $53,043, ranking #2,592 out of 3,222 counties — 29.4% below the national median. The poverty rate is 14.7% and unemployment stands at 3.3%.
Median Household Income Trend
Rankings →Income Distribution
Industry of Employment
Occupation
Housing
The median home value in St. Clair County is $157,100 (-44.3% vs national). Renters pay a median of $622/mo and the homeownership rate is 76.0%.
Median Home Value Trend
Rankings →Household Type
Education
In St. Clair County, 14.7% of adults age 25+ hold a bachelor's degree or higher, which is 56.4% below the national average, ranking #2,863 out of 3,222 counties.
Bachelor's Degree or Higher Trend
Rankings →Health & Wellbeing
Life expectancy in St. Clair County is 75.0 years. 22.1% of adults report poor or fair health and 12.3% lack health insurance. Data from County Health Rankings (2025).
Life Expectancy Trend
Substance Use
23.7% of adults in St. Clair County smoke , 41.1% are obese , and 20.3% report excessive drinking.
Adult Smoking Trend
Safety
The suicide rate is 19.8 per 100,000. Motor vehicle deaths occur at a rate of 36.3 per 100,000.
Suicide Rate Trend
Families & Children
27.8% of children in St. Clair County live in poverty . The teen birth rate is 27.0 per 1,000 females age 15–19.
Teen Birth Rate Trend
Civic & Transportation
Voter turnout in St. Clair County is 65.9%. The mean commute time is 29.5 min, which is 7.0% above the national average.
Voter Turnout Trend
Mean Commute Time Trend
Rankings →Elections
In the 2024 presidential election, St. Clair County voted Republican with a margin of 60.6%. The vote was 19.2% Dem / 79.8% Rep. Compared to 2020, the margin shifted 1.4 toward Republicans .
Vote Share Over Time
About St. Clair County, Missouri
St. Clair County, Missouri has a total population of 9,587, making it the 2,519th most populous county in the United States. The median age in St. Clair County is 46.1 years, which is 18.5% above the national median of 38.9 years.
The median household income in St. Clair County is $53,043, which ranks #2,592 of 3,222 counties nationwide. This is 29.4% below the national median of $75,149. The poverty rate is 14.7%, higher than the national rate of 12.6%. The unemployment rate stands at 3.3%.
The median home value in St. Clair County is $157,100, 44.3% below the national median. Renters in St. Clair County pay a median gross rent of $622 per month. The homeownership rate is 76.0%, compared to the national rate of 64.4%.
In St. Clair County, 14.7% of residents aged 25 and older hold a bachelor's degree or higher, 56.4% below the national average of 33.7%. Health insurance coverage stands at 89.4% of the population. The average commute time for workers is 29.5 min.
St. Clair County is a diverse community. The largest racial or ethnic group is White (non-Hispanic) at 92.8% of the population, followed by Two or More Races (3.8%) and Hispanic or Latino (2.2%).
All data for St. Clair County, Missouri comes from the U.S. Census Bureau's American Community Survey (ACS) 5-Year Estimates. These figures are estimates based on survey sampling and are subject to margin of error. For the most detailed and up-to-date data, visit the Census Bureau's official data portal.