County · Missouri
St. Charles County, Missouri
St. Charles County, Missouri. St. Charles County had 426,499 residents in 2025 by the Census Bureau's estimate, up 5.2% since 2020, faster than Missouri (+1.9%). It holds 18 places (17 cities, villages and boroughs and 1 census-designated) and 85 census tracts. GEOID 29183.
St. Charles County is one of the 15 counties of the St. Louis, MO-IL metropolitan statistical area (the Census Bureau's July 2023 delineation).
Residents, July 2025 estimate
426,499
Census Bureau estimate (no margin published)
2020 Census count: 405,262 · ACS 2020-2024: 414,535
Median household income
$104,692
±$1,179 (90% margin)
Missouri: $70,702
Median home value
$320,800
±$3,551 (90% margin)
Missouri: $230,300
Median gross rent
$1,370
±$21 (90% margin)
Missouri: $1,033
How many people live in St. Charles County, and is it growing?
The 2020 Census counted 405,262 residents in St. Charles County. The Census Bureau estimates 426,499 for July 1, 2025, up 5.2% since 2020, faster than Missouri (+1.9%). The 2020-2024 American Community Survey puts the population at 414,535 over 561 square miles of land.
| Measure | St. Charles County | Missouri | Change since 2015-2019 |
|---|---|---|---|
| Total population | 414,535 | 6,191,814 | +20,245 |
| Households | 161,311±694 | 2,508,227 | +14,680 |
| Average household size | 2.53±0.01 | 2.40 | −0.11 |
| Housing units | 167,163±126 | 2,825,287 | +12,890 |
St. Charles County's population since 2000
From 283,883 in 2000 to 426,499 in 2025: up 50.2%. The 2000, 2010 and 2020 figures are census counts. 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); PEP Vintage 2025 (CO-EST2025); 2020 Census · Check it at data.census.gov
What cities and towns are in St. Charles County?
St. Charles County holds 18 places: 17 cities, villages and boroughs (incorporated places) and 1 census-designated place. The largest is O'Fallon with 96,101 residents (2025 estimate). Places that cross a county line are listed with the share of their 2020 residents who live in this county.
| O'Fallon | 91,316 | $110,443 |
|---|---|---|
| St. Charles | 70,493 | $85,937 |
| St. Peters | 57,732 | $91,637 |
| Wentzville | 44,372 | $112,394 |
| Lake St. Louis | 16,707 | $125,693 |
| Dardenne Prairie | 12,743 | $152,500 |
| Cottleville | 5,611 | $131,310 |
| Weldon Spring | 5,326 | $158,548 |
| St. Paul | 3,005 | $159,022 |
| Flint Hill | 981 | $130,208 |
| New Melle | 541 | $114,375 |
| Josephville | 512 | $107,708 |
| West Alton | 359 | $111,500 |
| Portage Des SiouxGEOID 2959150 | 335 | $62,188 |
| ForistellGEOID 2925120 | 550 | $116,581 |
| Augusta | 270 | $103,750 |
| DefianceGEOID 2918910 | 159 | not published |
| Weldon Spring HeightsGEOID 2978334 | 93 | $143,750 |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); 2020 place-by-county parts · Check it at data.census.gov
Who lives in St. Charles County?
The median resident of St. Charles County is 39.8 years old; 22.5% are under 18 and 17.0% are 65 or older. The largest group is non-Hispanic white residents at 83.0%, then non-Hispanic Black residents at 5.0%. 4.5% of residents were born outside the United States.
| Measure | St. Charles County | Missouri | Change since 2015-2019 |
|---|---|---|---|
| Median age | 39.8±0.2 | 39.0 | +1.2 |
| Under 18 years | 22.5%±0.1 pts | 22.3% | – |
| 65 years and over | 17.0%±0.1 pts | 17.9% | – |
| Hispanic or Latino (any race) | 4.2% | 5.2% | +0.9 pts |
| White alone, not Hispanic | 83.0%±0.2 pts | 76.3% | −4.1 pts |
| Black or African American alone, not Hispanic | 5.0%±0.2 pts | 10.9% | +0.6 pts |
| Asian alone, not Hispanic | 3.0%±0.1 pts | 2.1% | +0.5 pts |
| American Indian and Alaska Native alone, not Hispanic | 0.0%±0.1 pts | 0.2% | – |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.0%±0.1 pts | 0.1% | – |
| Two or more races, not Hispanic | 4.3%±0.3 pts | 4.8% | – |
| Some other race alone, not Hispanic | 0.4%±0.1 pts | 0.4% | – |
| Born outside the United States | 4.5%±0.3 pts | 4.5% | +0.5 pts |
| Speak a language other than English at home (age 5+) | 5.8%±0.3 pts | 6.7% | – |
| Civilian veterans (age 18+) | 6.6%±0.3 pts | 7.3% | – |
| With a disability | 11.7%±0.4 pts | 14.9% | – |
| No health insurance coverage | 4.2%±0.3 pts | 8.8% | no clear change |
| High school graduate or higher (age 25+) | 95.7%±0.4 pts | 91.9% | – |
| Bachelor's degree or higher (age 25+) | 42.7%±0.8 pts | 32.4% | +3.8 pts |
| Graduate or professional degree (age 25+) | 15.8%±0.6 pts | 12.6% | – |
| Moved from another state in the past year | 1.9%±0.2 pts | 2.5% | – |
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 St. Charles County earn?
Half of St. Charles County's 161,311 households earn less than $104,692 a year (±$1,179), against $70,702 in Missouri. In 2015-2019 it was $104,582 in 2024 dollars; the margins of error cannot tell the two periods apart. 5.2% of residents live below the poverty line.
| Measure | St. Charles County | Missouri | Change since 2015-2019 |
|---|---|---|---|
| Median household income | $104,692±$1,179 | $70,702 | no clear change |
| Mean household income | $129,305±$2,781 | $96,247 | – |
| Per capita income | $51,051±$1,117 | $39,695 | +$3,124 |
| People below the poverty line | 5.2%±0.4 pts | 12.6% | no clear change |
| Children under 18 below the poverty line | 5.7%±0.8 pts | 15.8% | no clear change |
| Households receiving SNAP | 3.6%±0.4 pts | 9.8% | – |
| Households with a broadband subscription | 95.1%±0.4 pts | 89.3% | – |
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 St. Charles County?
Owners occupy 80.5% of St. Charles County's occupied homes and renters 19.5%. The median owner-occupied home is valued at $320,800 by its owner (±$3,551). The median renter pays $1,370 a month including utilities, and 34.5% of renters pay 35% or more of their income on rent.
| Measure | St. Charles County | Missouri | Change since 2015-2019 |
|---|---|---|---|
| Median home value (owner-occupied) | $320,800±$3,551 | $230,300 | +$51,155 |
| Median gross rent | $1,370±$21 | $1,033 | +$89 |
| Renters paying 35% or more of income on rent | 34.5%±2.3 pts | 36.6% | no clear change |
| Median monthly owner costs, with a mortgage | $1,866±$17 | $1,524 | – |
| Owner-occupied homes | 80.5%±0.6 pts | 68.1% | no clear change |
| Housing units | 167,163±126 | 2,825,287 | +12,890 |
| Homeowner vacancy rate | 0.3%±0.2 pts | 0.9% | – |
| Rental vacancy rate | 6.2%±1.3 pts | 5.0% | – |
| Single-family detached homes | 74.7%±0.7 pts | 70.5% | – |
| Mobile homes | 2.5%±0.3 pts | 5.2% | – |
| Built 2020 or later | 3.3%±0.3 pts | 1.6% | – |
| Built 1939 or earlier | 2.2%±0.3 pts | 13.3% | – |
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 St. Charles County building?
Builders took permits for 1,661 new housing units across St. Charles County in 2025 (1,270 single-family), 3.9 per 1,000 residents.
Source: Building Permits Survey, annual county files 2019-2025, U.S. Census Bureau · Census Building Permits Survey
How do people in St. Charles County get to work?
73.8% of St. Charles County's workers drive alone and 18.0% work from home. The average trip to work takes 24.5 minutes. The unemployment rate in 2020-2024 averaged 2.9%.
| Measure | St. Charles County | Missouri | Change since 2015-2019 |
|---|---|---|---|
| In the labor force (age 16+) | 69.4%±0.5 pts | 63.1% | – |
| Unemployment rate | 2.9%±0.3 pts | 4.0% | no clear change |
| Drove alone to work | 73.8%±0.9 pts | 74.8% | – |
| Carpooled | 5.9%±0.5 pts | 8.1% | – |
| Public transportation | 0.1%±0.1 pts | 0.8% | – |
| Walked | 0.8%±0.2 pts | 1.8% | – |
| Worked from home | 18.0%±0.8 pts | 13.0% | +12.4 pts |
| Mean travel time to work | 24.5 min±0.4 | 23.5 min | −1.3 min |
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 are St. Charles County's census tracts?
St. Charles County is divided into 85 census tracts. Among those with a reliable estimate, median household income runs from $48,676 (Tract 3105.01) to $170,625 (Tract 3111.03).
All 85 census tracts of St. Charles County, with their figures
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) · Check it at data.census.gov
How does St. Charles County compare with Missouri's other counties?
| Measure | Rank |
|---|---|
| Population | 3rd of 115 |
| Growth 2020-2025 | 18th of 115 |
| Residents per square mile | 4th of 115 |
| Median household income | 1st of 115 |
| Median home value | 2nd of 115 |
| Median gross rent | 1st of 115 |
| Poverty rate | 115th of 115 |
| Bachelor's degree or higher | 4th of 115 |
| Median age | 77th of 115 |
Source: PlainCities ranks 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 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 St. Charles County 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' school search.