St. Charles
Source:
Missouri
St. Charles is a county in Missouri with 13 ZIP codes and a total population of 362,252. All data is sourced from the U.S. Census Bureau American Community Survey (ACS) 2023 5-Year Estimates.
St. Charles is a county inside Missouri (FIPS code 29183) that contains 13 USPS ZIP codes covering a combined population of 362,252 according to Census ACS 5-Year Estimates. Counties are the natural bridge between state-level summaries and ZIP-level detail — crime statistics, HUD Fair Market Rents, and childcare pricing are all published at the county level, while household income and housing values are published at the ZIP level. This page reconciles the two views so you can see which ZIPs drive the county totals.
The 13 ZIPs listed below are ordered by population and each links to the full ZIP detail page with Census demographics, housing, income, home-price history, and cross-agency inputs. The most populated ZIP in St. Charles is 63376 covering Saint Peters with 70,828 residents at 658 people per square mile. Population density across ZIPs in this county varies — use the density column to spot urban cores versus rural delivery areas. A single county can contain both a dense downtown ZIP and a large rural ZIP covering several hundred square miles.
Because St. Charles uses FIPS code 29183, it joins cleanly to county-level federal datasets: HUD Fair Market Rent tables, FBI Uniform Crime Report data, and the Department of Labor National Database of Childcare Prices all key off the same code. That is how neighborhood scorecards combine ZIP-level Census demographics with county-level safety and affordability metrics. All data on this page comes from U.S. Census Bureau ACS 2023 5-Year Estimates and USPS ZIP Code Tabulation Area files — no estimates, no proprietary sources, no editorial scoring.
13
Total ZIPs
362,252
Total Population
ZIP Codes in St. Charles
Side-by-side: Compare 63376 vs 63301 →
| ZIP Code | City | Population | Density |
|---|---|---|---|
| 63376 | Saint Peters | 70,828 | 658 |
| 63301 | Saint Charles | 48,514 | 212 |
| 63366 | O Fallon | 46,175 | 259 |
| 63303 | Saint Charles | 45,834 | 893 |
| 63368 | O Fallon | 43,360 | 1,016 |
| 63304 | Saint Charles | 40,336 | 372 |
| 63385 | Wentzville | 35,750 | 206 |
| 63367 | Lake Saint Louis | 19,433 | 561 |
| 63348 | Foristell | 6,059 | 44 |
| 63341 | Defiance | 3,530 | 25 |
| 63332 | Augusta | 1,292 | 9 |
| 63373 | Portage Des Sioux | 603 | 14 |
| 63386 | West Alton | 538 | 7 |
Official Data Resources
What are common questions about ZIP codes in this county?
What is the population of St. Charles?▼
What ZIP codes are in St. Charles?▼
What is the median household income in St. Charles?▼
Source: U.S. Census Bureau, American Community Survey (ACS) 5-Year Estimates (2023). Verify with Census Bureau →
Source: HUD USPS Crosswalk (ZIP-to-county mapping). Verify with HUD →
PlainZIP is not affiliated with the U.S. Census Bureau or any government agency.
Read our methodology — how this data is sourced, computed, and verified.