Affton is a community in St. Louis County, Missouri, home to about 19,052 people across 4.6 square miles. Its ZIP code is 63123.
Homes sold for a median of $193 per square foot in the three months ending August 2026, a seller’s market.
Mostly Affton; also Concord and St. Louis
Each card is that ZIP code’s whole market, including any part outside Affton. Seller’s market: under 4 months of supply; buyer’s market: over 6. Methodology
We’re writing up Affton’s story and what everyday life there is like, for people thinking about moving in.
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| Nearest major airport | St. Louis Lambert International Airport (STL)14 miles away |
|---|---|
| Nearest city of 250,000+ | St. Louis, MO7 miles away |
| Nearest city of 1 million+ | Chicago, IL266 miles away |
Straight-line distances from the center of Affton; driving is longer.
Source: Airports from OurAirports (scheduled passenger service); city centers and populations from the U.S. Census Bureau.
Source: Members of Congress from the congress-legislators project; districts from the Census Bureau’s relationship files; governor and mayor from Wikidata.
Affton had 20,417 residents in the 2020 census, down 1% since 2000.
It’s the 41st largest of 1,060 towns in Missouri by population.
St. Louis County grew from 50,040 residents in 1900 to 1,004,125 in 2020.
St. Louis County, 1900–2020
Source: U.S. Census Bureau decennial censuses (counties 1900–1990 from the Bureau’s historical county file).
Average highs peak around 90°F in summer, and winter lows average 25°F. About 43.9 inches of rain and melted snow fall in a typical year.
Source: NOAA 1991–2020 climate normals, St Louis Sci Ctr, MO weather station (6 miles away).
629,036 jobs at 29,717 businesses in St. Louis County. The biggest industries by employees:
Source: U.S. Census Bureau County Business Patterns 2023 (private employers; jobs counted where people work).
264 doctors and other health care providers list an office in Affton.
Nearest hospitals
Providers with an office here
| Primary care doctors | 3 |
|---|---|
| Specialist doctors | 16 |
| Dentists | 14 |
| Nurse practitioners and physician assistants | 11 |
| Mental health providers | 152 |
| Physical and occupational therapists | 43 |
| Optometrists | 1 |
| Chiropractors | 24 |
| Pharmacies | 8 |
Source: Hospitals from CMS Hospital General Information (ratings are CMS overall star ratings); straight-line distances; providers from the CMS National Plan and Provider Enumeration System (NPPES), by practice address and primary specialty.
Parks (7 nearby)
Grocery stores (2 nearby)
Pharmacies
Libraries (2 nearby)
Museums
Theaters and performance venues
Counts are within about 1.5 miles of the center of town.
Source: Map data © OpenStreetMap contributors (openstreetmap.org/copyright), as mapped by volunteers; it can miss places or include closed ones.
Notable people born here
Source: Wikidata (wikidata.org), the free knowledge base; people are listed by place of birth.
Public schools here are run by Bayless, Affton 101, Lindbergh Schools. Check each district’s attendance zones for a specific address.
| School | Grades | Students | Type | Distance |
|---|---|---|---|---|
| Bayless ElementarySt Louis | Pre-K–5 | 858 | Public | 1.3 mi |
| Mesnier Primary Sch.St Louis | Pre-K–2 | 741 | Public | 0.9 mi |
| Dressel Elementary SchoolSt. Louis | K–5 | 598 | Public | 1.7 mi |
| Gotsch Intermediate Sch.St Louis | 3–5 | 562 | Public | 1.3 mi |
| Bayless Junior HighSt Louis | 6–8 | 385 | Public | 1.3 mi |
| Rogers MiddleSt Louis | 6–8 | 555 | Public | 1.8 mi |
| Affton HighSt Louis | 9–12 | 761 | Public | 0.8 mi |
| Bayless Senior HighSt Louis | 9–12 | 562 | Public | 1.3 mi |
| School | Grades | Students | Affiliation | Distance |
|---|---|---|---|---|
| Holy Cross AcademySaint Louis | Pre-K–8 | 402 | Roman Catholic | 2.1 mi |
| Holy Cross Acadmey Early ChildhoodSaint Louis | Pre-K–TK | 10 | Roman Catholic | 1.5 mi |
| Salem Lutheran SchoolAffton | Pre-K–8 | 84 | Lutheran Church–Missouri Synod | 1.3 mi |
| St Simon the ApostleSaint Louis | Pre-K–8 | 128 | Roman Catholic | 2.0 mi |
| Cor Jesu AcademySaint Louis | 9–12 | 519 | Roman Catholic | 1.1 mi |
| Lutheran High School SouthSaint Louis | 9–12 | 550 | Lutheran Church–Missouri Synod | 0.6 mi |
Source: U.S. Department of Education, NCES: Common Core of Data (2024-2025) for public schools; Private School Universe Survey (2023-2024) for private schools. Listed by address; we don’t rate schools.
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Shares ZIP codes with Concord, St. Louis, Green Park, Crestwood, St. George, Lakeshire, Marlborough, Grantwood Village and Wilbur Park.
Town boundaries don’t always match ZIP codes: a ZIP code can cross into neighboring towns, and a town can share a ZIP code with its neighbors. Facts describe the town itself; market figures describe whole ZIP codes.