Lake St. Louis, Missouri Demographics & Population 2026
During the 2020–2024 ACS period, Lake St. Louis, Missouri had a total population of 18,066, the 47th largest city in Missouri, with a median household income of $125,693, which is 78% higher than the state average. The poverty rate is 4.3%.
Data vintage: U.S. Census Bureau ACS 2020–2024 5-Year Estimates · refreshed July 2026 · Methodology & source notes
Key Takeaways
- Household income is 78% above the state average — one of the wealthiest communities in Missouri.
- An exceptionally low poverty rate of 4.3% — among the lowest in Missouri.
- 51.7% of adults hold a bachelor's degree or higher — top 10% in Missouri.
Lake St. Louis Quick Facts
How Lake St. Louis Changed
Change from the 2019–2023 ACS period to 2020–2024. These are rolling five-year estimates, not year-over-year measurements.
| Metric | 2019–2023 | 2020–2024 | Change |
|---|---|---|---|
| Population | 17,538 | 18,066 | +3.0% |
| Median household income | $123,427 | $125,693 | +1.8% |
| Median home value | $375,300 | $405,900 | +8.2% |
How Lake St. Louis Compares
Median Household Income
Median Home Value
Economy & Housing
Household Income Distribution
Detailed income brackets
Employment
Housing Overview
People & Demographics
Age Distribution
Race & Ethnicity
Diversity Index
A less diverse community where one racial or ethnic group represents a large majority.
State average: 40 | National average: 61
Education
Educational Attainment (Adults 25+)
Lake St. Louis Rankings in Missouri
Explore Missouri Rankings
Other Cities in St. Charles County
| City | Population | Median Income | Poverty | Home Value |
|---|---|---|---|---|
| O'Fallon | 93,801 | $110,443 | 5.4% | $326,200 |
| St. Charles | 71,508 | $85,937 | 7.3% | $298,700 |
| St. Peters | 59,092 | $91,637 | 5.7% | $269,900 |
| Wentzville | 47,061 | $112,394 | 5.4% | $331,300 |
| Dardenne Prairie | 13,503 | $152,500 | 1.3% | $432,000 |
| Cottleville | 5,937 | $131,310 | 2.0% | $435,400 |
| Weldon Spring | 5,310 | $158,548 | 0.7% | $544,300 |
| St. Paul | 3,456 | $159,022 | 0.5% | $443,600 |
| Foristell | 1,096 | $116,581 | 1.7% | $431,700 |
| Josephville | 664 | $107,708 | 18.1% | $494,600 |
Cities Similar to Lake St. Louis
These cities in the same state have comparable population and economic profiles.
| City | Population | Median Income | Home Value | Bachelor's+ | Poverty |
|---|---|---|---|---|---|
| Creve Coeur | 18,643 | $127,188 | $614,000 | 70.1% | 6.1% |
| Clayton | 17,380 | $123,000 | $830,000 | 84.9% | 8.0% |
| Manchester | 18,160 | $97,801 | $323,100 | 62.4% | 6.4% |
| Concord | 18,368 | $89,038 | $303,600 | 42.0% | 3.9% |
| Old Jamestown | 20,651 | $99,521 | $236,100 | 39.6% | 7.4% |
Population Overview
Lake St. Louis is a small city located in Missouri, within St. Charles County. The total population is 18,066. It ranks as the 47th most populous out of 1,062 Census-designated places in Missouri.
Age Demographics
The median age in Lake St. Louis is 42.7 years. This is 9% higher than the state median of 39.0 years. 10.3% of residents are 75 or older, suggesting a significant retirement-age population with implications for healthcare services and senior housing.
Economy, Income & Housing
The median household income in Lake St. Louis is $125,693. This is 78% higher than the state median of $70,702. It is also 56% higher than the national median of $80,734. The poverty rate stands at 4.3%. This is 65% lower than the state poverty rate of 12.6%. This exceptionally low poverty rate indicates strong economic prosperity across the community. The unemployment rate is 4.7%. This is 18% higher than the state rate of 4.0%. The median home value is $405,900. Housing costs are 76% higher than the state median of $230,300. The home-value-to-income ratio is 3.2x. 75.6% of occupied housing units are owner-occupied. This homeownership rate is 11% higher than the state average of 68.1%.
Race & Ethnicity
The largest racial or ethnic group in Lake St. Louis is White (non-Hispanic), making up 84.7% of the population. Black or African American residents account for 5.5%. The Hispanic or Latino population (2.5%) is well below the state average of 5.2%.
Education
51.7% of residents aged 25 and older hold a bachelor's degree or higher. This places Lake St. Louis in the top 10% of all cities in the state for educational attainment. This is 60% higher than the state rate of 32.4%. Nationally, 35.7% of adults hold at least a bachelor's degree. The high school graduation rate (or equivalent) is 97.0%. Notably, 17.6% of adults hold a graduate or professional degree, indicating a highly educated workforce.
Data Sources & Methodology
All demographic data for Lake St. Louis, Missouri is sourced from the U.S. Census Bureau's American Community Survey (ACS) 2020–2024 5-Year Estimates. The ACS collects data from approximately 3.5 million households annually and pools five years of responses so that even small communities can be measured, though the margin of error widens as the population falls. Comparisons are made against Missouri state averages and national averages calculated from the same dataset. Rankings reflect the city's position among all 1,062 Census-designated places in Missouri. Read more about how these figures are produced on our methodology page, or visit data.census.gov for official data.
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Frequently Asked Questions
What is the population of Lake St. Louis, Missouri?
Lake St. Louis, Missouri has a population of 18,066 according to the most recent U.S. Census ACS 5-Year Estimates.
What is the median household income in Lake St. Louis, MO?
The median household income in Lake St. Louis is $125,693, which is 56% higher than the national median of $80,734.
What is the poverty rate in Lake St. Louis, MO?
The poverty rate in Lake St. Louis is 4.3%. This means approximately 785 residents live below the federal poverty line.
What is the racial makeup of Lake St. Louis, Missouri?
Lake St. Louis's population is 84.7% White, 5.5% Black, 2.5% Hispanic/Latino, and 1.9% Asian.
What is the median home value in Lake St. Louis, MO?
The median home value in Lake St. Louis is $405,900. The home-value-to-income ratio is 3.2x.
How educated is Lake St. Louis, Missouri?
51.7% of adults (25+) in Lake St. Louis hold a bachelor's degree or higher, and 17.6% hold a graduate or professional degree.