Lake St. Louis is a city located in St. Charles County, Missouri. Lake St. Louis has a 2025 population of 19,752 . Lake St. Louis is currently growing at a rate of 3.09% annually and its population has increased by 17.65% since the most recent census, which recorded a population of 16,789 in 2020.
The average household income in Lake St. Louis is $148,931 with a poverty rate of 4.05%. The median age in Lake St. Louis is 43.2 years: 41.7 years for males, and 44.7 years for females. For every 100 females there are 98.3 males.
Data after 2023 is projected based on recent change
The racial composition of Lake St. Louis includes 87.57% White, 4.24% Black or African American, and smaller percentages for Asian, other race, Native American and multiracial populations.
White (87.57%)
Two or more races (5.56%)
Black or African American (4.24%)
Asian (1.56%)
Other race (1.01%)
Native American (0.06%)
Race | Population | Percentage (of total) |
|---|---|---|
| White | 15,358 | 87.57% |
| Two or more races | 975 | 5.56% |
| Black or African American | 744 | 4.24% |
| Asian | 273 | 1.56% |
| Other race | 178 | 1.01% |
| Native American | 10 | 0.06% |
Married
Widowed
Divorced
Separated
Never Married
Lake St. Louis' average per capita income is $73,744. Household income levels show a median of $123,427. The poverty rate stands at 4.05%.
Name | Median | Mean |
|---|---|---|
| Married Families | $157,753 | - |
| Families | $151,721 | $174,546 |
| Households | $123,427 | $148,931 |
| Non Families | $53,474 | $74,883 |
Average Income
Median Household Income
Poverty Rate