Population 76,872 · Census ACS 2020–24
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Population and households in O'fallon
Household size in O'fallon
| Period | O'fallon | St. Louis area | Missouri | U.S. |
|---|---|---|---|---|
| 2006–10 | 2.76 | 2.52 | 2.49 | 2.68 |
| 2010–14 | 2.78 | 2.53 | 2.52 | 2.73 |
| 2015–19 | 2.78 | 2.49 | 2.50 | 2.71 |
| 2020–24 | 2.64 | 2.46 | 2.49 | 2.65 |
| Change | −0.12 | −0.06 | −0.00 | −0.03 |
Households in O'fallon average 2.64 people, about the same as the country as a whole (2.65). The typical household here is bigger than in the St. Louis area overall, where it has 2.46 people. Since 2006–10, household size has dropped from 2.76, a much bigger shift than nationally.
Household size: the average number of people living in each occupied home. Source: BestNeighborhood calculations from U.S. Census Bureau ACS 5-year block-group estimates (table B25010).
Median age in O'fallon
| Period | O'fallon | St. Louis area | Missouri | U.S. |
|---|---|---|---|---|
| 2006–10 | 34.3 | 38.5 | 38.4 | 37.7 |
| 2010–14 | 36.6 | 39.5 | 39.2 | 38.6 |
| 2015–19 | 38.7 | 40.7 | 40.0 | 39.6 |
| 2020–24 | 39.7 | 40.8 | 40.1 | 40.1 |
| Change | +5.4 | +2.3 | +1.7 | +2.3 |
At 39.7, the median age in O'fallon is close to the national median of 40.1, so its age mix looks much like the country's. The median age has climbed from 34.3 in 2006–10, in line with the national trend. The youngest areas are in the southwest, the oldest in the northeast.
Median age: the age that splits residents into two equal halves. Source: BestNeighborhood calculations from U.S. Census Bureau ACS 5-year block-group estimates (table B01002).
Single-parent households in O'fallon
| Period | O'fallon | St. Louis area | Missouri | U.S. |
|---|---|---|---|---|
| 2006–10 | 8.4% | 11.7% | 11.3% | 12.3% |
| 2010–14 | 10.5% | 11.5% | 11.4% | 12.3% |
| 2015–19 | 10.2% | 11.0% | 10.9% | 11.6% |
| 2020–24 | 9.7% | 11.1% | 11.0% | 11.6% |
| Change | +1.3 pts | −0.6 pts | −0.3 pts | −0.6 pts |
Single parents head about one in ten households in O'fallon (9.7%), a little below the national share of 11.6%. The single-parent share is up 1.3 points from 2006–10, even as the national share fell.
Single-parent households: households where one adult with no spouse present lives with children under 18. Source: BestNeighborhood calculations from U.S. Census Bureau ACS 5-year block-group estimates (table B11003).
Housing in O'fallon
Renters in O'fallon
| Period | O'fallon | St. Louis area | Missouri | U.S. |
|---|---|---|---|---|
| 2006–10 | 14.8% | 28.3% | 30.0% | 33.3% |
| 2010–14 | 20.5% | 30.1% | 32.1% | 35.6% |
| 2015–19 | 18.5% | 31.1% | 33.2% | 36.0% |
| 2020–24 | 20.4% | 29.6% | 31.9% | 34.8% |
| Change | +5.6 pts | +1.4 pts | +1.9 pts | +1.5 pts |
O'fallon is largely a place of homeowners: only 20.4% of households rent, far below the national share of 34.8%. Owner-heavy areas like this tend to see less turnover. Among homeowners, 28.1% have no mortgage at all, well below the national share of 39.8%. The renter share has risen 5.6 points since 2006–10, a much bigger shift than nationally.
Renters: occupied homes that are rented rather than owned. Source: BestNeighborhood calculations from U.S. Census Bureau ACS 5-year block-group estimates (table B25003).
Vacant homes in O'fallon
| Period | O'fallon | St. Louis area | Missouri | U.S. |
|---|---|---|---|---|
| 2006–10 | 5.6% | 9.6% | 11.6% | 11.4% |
| 2010–14 | 5.0% | 10.1% | 12.0% | 11.4% |
| 2015–19 | 4.3% | 10.1% | 12.2% | 11.1% |
| 2020–24 | 3.7% | 8.8% | 10.5% | 9.6% |
| Change | −1.8 pts | −0.8 pts | −1.1 pts | −1.8 pts |
Only 3.7% of homes in O'fallon are vacant, far below the national rate of 9.6%, which usually means strong demand for housing. Since 2006–10, vacancy has fallen 1.8 points, in line with the national trend. Of the 191 Missouri cities with 5,000+ people, only 14 have a lower vacancy rate.
Vacant homes: homes with no one living in them, including vacation homes and homes for sale or rent. Source: BestNeighborhood calculations from U.S. Census Bureau ACS 5-year block-group estimates (table B25002).
Age of homes in O'fallon
| Period | O'fallon | St. Louis area | Missouri | U.S. |
|---|---|---|---|---|
| 2006–10 | 1995 | 1972 | 1974 | 1974 |
| 2010–14 | 1996 | 1972 | 1975 | 1975 |
| 2015–19 | 1997 | 1973 | 1976 | 1977 |
| 2020–24 | 1996 | 1975 | 1978 | 1980 |
| Change | +1 | +3 | +4 | +6 |
O'fallon has newer housing than the country as a whole: the median home was built in 1996, versus 1980 nationally. Newer construction is concentrated in the southwest, while the northeast has the oldest housing. O'fallon has newer homes than the great majority of Missouri cities.
Age of homes: the year that splits the housing stock into older and newer halves. Source: BestNeighborhood calculations from U.S. Census Bureau ACS 5-year block-group estimates (table B25035).
Rent in O'fallon
| Period | O'fallon | St. Louis area | Missouri | U.S. |
|---|---|---|---|---|
| 2006–10 | $930 | $825 | $740 | $965 |
| 2010–14 | $1,164 | $920 | $816 | $1,040 |
| 2015–19 | $1,168 | $1,010 | $899 | $1,213 |
| 2020–24 | $1,403 | $1,239 | $1,122 | $1,571 |
| Change | +$473 | +$414 | +$383 | +$606 |
The median renter in O'fallon pays $1,403 a month for rent and utilities, below the national median of $1,571. Even so, rents here are higher than in the St. Louis area overall ($1,239). Rents are up $473 a month from 2006–10, a 51% rise, a slower climb than the nation's. Rent takes 31.5% of the typical renter's income, just over the 30% mark often used to define affordable rent.
Rent: monthly rent plus the utilities renters pay themselves. Source: BestNeighborhood calculations from U.S. Census Bureau ACS 5-year block-group estimates (table B25064).
Education in O'fallon
Bachelor's degrees in O'fallon
| Period | O'fallon | St. Louis area | Missouri | U.S. |
|---|---|---|---|---|
| 2006–10 | 34.3% | 30.3% | 26.0% | 28.4% |
| 2010–14 | 35.0% | 32.1% | 27.3% | 29.6% |
| 2015–19 | 38.1% | 34.9% | 29.6% | 32.1% |
| 2020–24 | 39.3% | 38.5% | 32.6% | 35.6% |
| Change | +5.0 pts | +8.3 pts | +6.6 pts | +7.2 pts |
About four in ten adults 25 and older in O'fallon (39.3%) have a bachelor's degree or higher, a bit above the national share of 35.6%. Since 2006–10, the share with a degree has risen 5.0 points, as it has nationally. College graduates are most concentrated in the southeast and least in the west.
Bachelor's degrees: adults 25 and older with a bachelor's degree or higher. Source: BestNeighborhood calculations from U.S. Census Bureau ACS 5-year block-group estimates (table B15003).
High school graduates in O'fallon
| Period | O'fallon | St. Louis area | Missouri | U.S. |
|---|---|---|---|---|
| 2006–10 | 91.9% | 88.8% | 86.8% | 84.9% |
| 2010–14 | 93.3% | 90.5% | 88.3% | 86.1% |
| 2015–19 | 95.0% | 92.1% | 90.0% | 87.7% |
| 2020–24 | 94.7% | 93.6% | 91.8% | 89.3% |
| Change | +2.8 pts | +4.8 pts | +5.1 pts | +4.3 pts |
High school completion is high in O'fallon: 94.7% of adults 25 and older have a diploma or equivalent, well above the national rate of 89.3%. That is in line with the rest of the St. Louis area. The share with a diploma is up 2.8 points from 2006–10, in line with the national trend.
High school graduates: adults 25 and older with a high school diploma, GED or more. Source: BestNeighborhood calculations from U.S. Census Bureau ACS 5-year block-group estimates (table B15003).
Jobs in O'fallon
| Period | O'fallon | St. Louis area | Missouri | U.S. |
|---|---|---|---|---|
| 2006–10 | 5.8% | 7.7% | 7.4% | 8.1% |
| 2010–14 | 5.9% | 8.8% | 8.4% | 9.4% |
| 2015–19 | 2.7% | 4.9% | 4.6% | 5.6% |
| 2020–24 | 3.5% | 4.3% | 4.1% | 5.4% |
| Change | −2.3 pts | −3.4 pts | −3.3 pts | −2.7 pts |
Jobs have been easier to find in O'fallon than nationally: unemployment was 3.5%, against 5.4%. Unemployment is down 2.3 points from 2006–10, in line with the national trend. Each figure pools five years of surveys (2020–24), so it describes that whole stretch rather than today's job market.
Unemployment: people looking for work as a share of everyone working or looking. Source: BestNeighborhood calculations from U.S. Census Bureau ACS 5-year block-group estimates (table B23025).
O'fallon compared with nearby cities
| City | Household size | Median age | Single parents | Renters | Vacant homes | Median year built | Median rent | Bachelor's degree | High school diploma | Unemployment |
|---|---|---|---|---|---|---|---|---|---|---|
| O'fallon | 2.64 | 39.7 | 9.7% | 20.4% | 3.7% | 1996 | $1,403 | 39.3% | 94.7% | 3.5% |
| Dardenne Prairie | 2.79 | 41.1 | 8.1% | 17.6% | 3.8% | 2002 | $1,561 | 53.5% | 98.5% | 2.2% |
| Cottleville | 2.77 | 43.1 | 6.5% | 11.4% | 5.1% | 1998 | $1,790 | 48.8% | 97.5% | 2.0% |
| Lake St. Louis | 2.75 | 41.2 | 7.1% | 16.8% | 4.4% | 2002 | $1,660 | 51.5% | 97.3% | 3.1% |
| St. Paul | 2.93 | 39.3 | 6.9% | 1.8% | 3.9% | 2010 | $1,391 | 44.7% | 97.8% | 0.6% |
| St. Peters | 2.52 | 41.7 | 8.4% | 18.2% | 4.7% | 1988 | $1,493 | 39.3% | 95.6% | 2.7% |
| Josephville | 2.85 | 39.7 | 5.6% | 9.2% | 3.0% | 2006 | $1,053 | 39.3% | 95.9% | 2.7% |
| Weldon Spring Heights | 2.62 | 49.7 | 3.6% | 20.2% | 10.4% | 2000 | $3,382 | 58.2% | 96.9% | 0.4% |
| Weldon Spring | 2.66 | 46.9 | 6.5% | 12.4% | 4.1% | 1995 | $2,616 | 59.5% | 98.6% | 3.4% |
| Peruque | 2.06 | 40.3 | 12.1% | 53.2% | 10.0% | 1969 | $1,164 | 8.5% | 84.2% | 0.0% |
| Wentzville | 2.85 | 37.6 | 9.8% | 16.7% | 2.9% | 2005 | $1,361 | 40.3% | 94.1% | 2.9% |
All figures 2020–24.
Cities with similar populations: Oviedo, FL · Olympia, WA · Oceanside, CA · Madera, CA · Maryville, TN · Marysville, WA · Lynchburg, VA · McKinney, TX · Madison, WI · Long Beach, CA
About these numbers
Every figure on this page is a BestNeighborhood calculation from the Census Bureau's American Community Survey (ACS), built up from the Census block groups that make up O'fallon. Each ACS 5-year release pools five years of responses; this page shows the last 15 releases, 2006–10 through 2020–24. Neighboring releases share four of their five years, so they move gradually and small changes between them are within the survey's margin of error; in small places the lines can jump from one release to the next for the same reason. The maps show the same measures for each neighborhood, ranked against the whole country.
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