City · Missouri
Lake St. Louis, Missouri
Lake St. Louis, city, in St. Charles County, Missouri. Lake St. Louis had 19,129 residents on July 1, 2025 by the Census Bureau's estimate, up 14.4% since 2020; the 2020 Census counted 16,707 and the ACS 2020-2024 5-year estimates put it at 18,066 (±32). GEOID 2940043.
Residents, July 2025 estimate
19,129
Census Bureau estimate (no margin published)
2020 Census count: 16,707 · ACS 2020-2024: 18,066 ±32
Median household income
$125,693
±$12,310 (90% margin)
Missouri: $70,702
Median home value
$405,900
±$24,017 (90% margin)
Missouri: $230,300
Median gross rent
$1,588
±$138 (90% margin)
Missouri: $1,033
Where is Lake St. Louis and what county is it in?
Lake St. Louis is a city in St. Charles County, Missouri. It covers 8.5 square miles of land, 1,954 residents per square mile in 2020.
Lake St. Louis is in the St. Louis, MO-IL metropolitan statistical area, which takes in 15 counties (Census Bureau delineation, July 2023).
Source: 2024 Gazetteer and 2020 place-by-county files, U.S. Census Bureau · Census reference files
How many people live in Lake St. Louis, and is it growing?
The Census Bureau estimates that 19,129 people lived in Lake St. Louis on July 1, 2025, up 14.4% since 2020, faster than Missouri (+1.9%). The 2020 Census counted 16,707 residents. The 2020-2024 American Community Survey, a five-year sample, puts the population at 18,066 (±32).
| Measure | Lake St. Louis | St. Charles County | Change since 2015-2019 |
|---|---|---|---|
| Total population | 18,066 ±32 | 414,535 | +2,077 |
| Households | 7,351 ±317 | 161,311 | +1,093 |
| Average household size | 2.46 ±0.11 | 2.53 | no clear change |
| Housing units | 7,657 ±323 | 167,163 | +957 |
Lake St. Louis's population since 2000
From 10,169 in 2000 to 19,129 in 2025: up 88.1%. The 2000, 2010 and 2020 figures are census counts, each for Lake St. Louis as it was drawn that year: a place that annexed land, or a community that has since incorporated, covered a different area then. The 2005 figure is the Census Bureau's intercensal estimate, revised to fit the 2000 and 2010 counts and drawn on 2010 boundaries; 2015 and 2025 are July 1 estimates made from the census before them.
Source: The 2000, 2010 and 2020 Census counts and the Census Bureau's population estimates (intercensal 2000-2010, Vintage 2020, Vintage 2025) · Census population estimates
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); Census PEP Vintage 2025 (SUB-EST2025, CO-EST2025); 2020 Census P.L. 94-171 · Check it at data.census.gov
Who lives in Lake St. Louis?
The median resident of Lake St. Louis is 42.7 years old; 20.1% are under 18 and 20.5% are 65 or older. The largest group is non-Hispanic white residents at 84.7%, then non-Hispanic Black residents at 5.5%. 4.0% of residents were born outside the United States.
| Measure | Lake St. Louis | St. Charles County | Change since 2015-2019 |
|---|---|---|---|
| Median age | 42.7 ±2.7 | 39.8 | no clear change |
| Under 18 years | 20.1% ±1.8 pts | 22.5% | – |
| 65 years and over | 20.5% ±2.2 pts | 17.0% | – |
| Male | 50.5% ±2.4 pts | 49.5% | – |
| Hispanic or Latino (any race) | 2.5% ±1.1 pts | 4.2% | −2.8 pts |
| White alone, not Hispanic | 84.7% ±3.5 pts | 83.0% | no clear change |
| Black or African American alone, not Hispanic | 5.5% ±2.3 pts | 5.0% | – |
| Asian alone, not Hispanic | 1.9% ±1.1 pts | 3.0% | no clear change |
| American Indian and Alaska Native alone, not Hispanic | 0.0% ±0.1 pts | 0.0% | – |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.0% ±0.2 pts | 0.0% | – |
| Two or more races, not Hispanic | 4.8% ±2.0 pts | 4.3% | – |
| Some other race alone, not Hispanic | 0.6% ±0.5 pts | 0.4% | – |
| Born outside the United States | 4.0% ±1.3 pts | 4.5% | no clear change |
| Speak a language other than English at home (age 5+) | 4.6% ±1.3 pts | 5.8% | – |
| Civilian veterans (age 18+) | 8.7% ±1.8 pts | 6.6% | – |
| With a disability | 10.8% ±2.0 pts | 11.7% | – |
| No health insurance coverage | 3.5% ±1.3 pts | 4.2% | no clear change |
| High school graduate or higher (age 25+) | 97.0% ±1.8 pts | 95.7% | – |
| Bachelor's degree or higher (age 25+) | 51.7% ±4.0 pts | 42.7% | +6.6 pts |
| Graduate or professional degree (age 25+) | 17.6% ±2.5 pts | 15.8% | – |
| Lived in the same house a year earlier | 85.0% ±3.3 pts | 89.6% | – |
| Moved from another state in the past year | 2.6% ±1.1 pts | 1.9% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profiles DP02, DP05) · Check it at data.census.gov
What do households in Lake St. Louis earn?
Half of Lake St. Louis's 7,351 households earn less than $125,693 a year (±$12,310), against $104,692 in St. Charles County and $70,702 in Missouri. In 2015-2019 it was $113,591 in 2024 dollars; the margins of error cannot tell the two periods apart. 4.3% of residents live below the poverty line.
| Measure | Lake St. Louis | St. Charles County | Change since 2015-2019 |
|---|---|---|---|
| Median household income | $125,693 ±$12,310 | $104,692 | no clear change |
| Mean household income | $155,073 ±$12,765 | $129,305 | – |
| Per capita income | $62,954 ±$5,079 | $51,051 | +$7,223 |
| People below the poverty line | 4.3% ±1.7 pts | 5.2% | no clear change |
| Children under 18 below the poverty line | 0.2% ±0.4 pts | 5.7% | – |
| Households receiving SNAP | 1.4% ±1.4 pts | 3.6% | – |
| Households with a computer | 98.9% ±1.2 pts | 97.4% | – |
| Households with a broadband subscription | 98.3% ±1.3 pts | 95.1% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What does housing cost in Lake St. Louis?
Owners occupy 75.6% of Lake St. Louis's occupied homes and renters 24.4%. The median owner-occupied home is valued at $405,900 by its owner (±$24,017). The median renter pays $1,588 a month including utilities, and 23.9% of renters pay 35% or more of their income on rent.
| Measure | Lake St. Louis | St. Charles County | Change since 2015-2019 |
|---|---|---|---|
| Median home value (owner-occupied) | $405,900 ±$24,017 | $320,800 | +$68,198 |
| Median gross rent | $1,588 ±$138 | $1,370 | +$197 |
| Renters paying 35% or more of income on rent | 23.9% ±8.7 pts | 34.5% | no clear change |
| Median monthly owner costs, with a mortgage | $2,225 ±$116 | $1,866 | – |
| Owner-occupied homes | 75.6% ±3.7 pts | 80.5% | no clear change |
| Renter-occupied homes | 24.4% ±3.7 pts | 19.5% | – |
| Housing units | 7,657 ±323 | 167,163 | +957 |
| Homeowner vacancy rate | 0.3% ±0.5 pts | 0.3% | – |
| Rental vacancy rate | 11.9% ±8.8 pts | 6.2% | – |
| Single-family detached homes | 66.8% ±3.6 pts | 74.7% | – |
| Mobile homes | 0.0% ±0.5 pts | 2.5% | – |
| Built 2020 or later | 9.8% ±2.7 pts | 3.3% | – |
| Built 2010 to 2019 | 14.8% ±3.2 pts | 14.4% | – |
| Built 1939 or earlier | 0.0% ±0.5 pts | 2.2% | – |
| Households with no vehicle | 2.1% ±1.3 pts | 3.8% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP04) · Check it at data.census.gov
How many new homes is Lake St. Louis building?
Builders took permits for 153 new housing units in Lake St. Louis in 2025 (75 in single-family houses), 8.0 per 1,000 residents against 2.8 across Missouri.
Counts of units in permits a local office issued; not every permitted unit is built. A year marked with months was reported for part of the year.
Source: Building Permits Survey, annual place files 2019-2025, U.S. Census Bureau · Census Building Permits Survey
How do people in Lake St. Louis work and get to work?
71.3% of Lake St. Louis's workers drive alone and 21.9% work from home. The average trip to work takes 25.6 minutes. The unemployment rate in 2020-2024 averaged 4.7%.
| Measure | Lake St. Louis | St. Charles County | Change since 2015-2019 |
|---|---|---|---|
| In the labor force (age 16+) | 66.4% ±3.2 pts | 69.4% | – |
| Unemployment rate | 4.7% ±1.7 pts | 2.9% | no clear change |
| Drove alone to work | 71.3% ±3.6 pts | 73.8% | – |
| Carpooled | 6.1% ±2.0 pts | 5.9% | – |
| Public transportation | 0.0% ±0.4 pts | 0.1% | – |
| Walked | 0.5% ±0.5 pts | 0.8% | – |
| Worked from home | 21.9% ±3.4 pts | 18.0% | +14.7 pts |
| Mean travel time to work | 25.6 min ±1.9 | 24.5 min | no clear change |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What census tracts are in Lake St. Louis?
3 census tracts lie mostly in Lake St. Louis, and 8 more reach into it (2020 census blocks). Their median household incomes run from $115,428 (Tract 3119.03) to $155,570 (Tract 3119.09).
| Tract | Residents, 2020-2024 | Median household income |
|---|---|---|
| Tract 3119.03St. Charles County | 6,294 | $115,428 |
| Tract 3119.09St. Charles County | 5,169 | $155,570 |
| Tract 3119.08St. Charles County | 5,979 | $144,625 |
| Tract 3119.04St. Charles County | 7,234 | $120,647 |
| Tract 3122.07St. Charles County | 4,404 | $93,070 |
| Tract 3122.08St. Charles County | 4,912 | $142,841 |
| Tract 3122.09St. Charles County | 5,590 | $165,417 |
| Tract 3111.53St. Charles County | 7,522 | $107,841 |
| Tract 3120.95St. Charles County | 7,866 | $124,194 |
| Tract 3119.07St. Charles County | 6,021 | $65,052 |
| Tract 3118.02St. Charles County | 6,264 | $88,320 |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); 2020 block assignment files (tract share = share of the tract's census blocks in Lake St. Louis) · Census block assignment files
How does Lake St. Louis compare with other places in Missouri?
By the Census Bureau's July 2025 estimates, Lake St. Louis is the 2,011th-most populous of the 19,476 U.S. incorporated places that have one and the 39th-most populous of 936 in Missouri.
Lake St. Louis ranks 22nd of 416 places in Missouri with 1,000 or more residents and a reliable estimate, by median household income.
| Measure | Rank | Of |
|---|---|---|
| Population, July 2025 estimate | 39th | 936 |
| Growth 2020-2025 (PEP) | 21st | 394 |
| Residents per square mile | 79th | 420 |
| Median household income | 22nd | 416 |
| Per capita income | 26th | 420 |
| Median home value | 27th | 416 |
| Median gross rent | 16th | 398 |
| Poverty rate | 358th | 373 |
| Bachelor's degree or higher | 38th | 404 |
| Median age | 86th | 420 |
| Owner-occupied share | 113th | 418 |
| Work from home | 30th | 270 |
| Travel time to work | 129th | 420 |
Lake St. Louis's figures with every place in Missouri (CSV)
Every place in Missouri, sortable · Compare Lake St. Louis with other places
Source: PlainCities ranks computed from the American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) and PEP Vintage 2025 · How ranks are computed
How reliable are the figures for Lake St. Louis?
11 of the 57 figures for Lake St. Louis on this page carry a coefficient of variation over 40% and are marked with a ring: they come from a small sample, so read them as rough.
The American Community Survey samples about one household in eight over five years, so every figure is an estimate with a 90% margin of error (shown under each value). A ring marks an estimate whose coefficient of variation is over 40%. A change is called only when the gap between the two periods is larger than their combined 90% margin (the square root of the sum of the two squared margins), the Census Bureau's test. How to read a margin of error.
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026): margins of error as published · ACS technical documentation
How these figures are made: methodology and release checks · reading a margin of error · every state · corrections
Not on this page: crime, weather and schools for Lake St. Louis are other agencies' records. Crime: the FBI's Crime Data Explorer · climate: NOAA's U.S. Climate Normals · schools: the National Center for Education Statistics' public schools in Lake St. Louis.