Belleville
RANK #344 / 996 NAT · #22 / 28 IL · POP 256,791
1YR FORECAST: +1.7%
5YR OUTLOOK: +28%
Home to the Cahokia Mounds State Historic Site, a UNESCO World Heritage site, St. Clair County, Illinois, offers a blend of historical significance and modern living. Located directly east of St. Louis, Missouri, the county provides residents with various commute options, including the MetroLink light rail system and bus routes, connecting them to the wider St. Louis metropolitan area. The community offers numerous parks and recreational facilities, such as Belleville's Bicentennial Park and Shiloh's Engelmann Farm Park, providing walking trails and green spaces.
Life in the county is characterized by a mix of families and young professionals, with many residents owning their homes. Public schools in towns like O'Fallon and Mascoutah are noted for their quality. The economy is driven by sectors such as healthcare, manufacturing, and transportation, with Scott Air Force Base and MidAmerica St. Louis Airport serving as significant employers. Recent economic developments include investments in infrastructure and manufacturing, alongside efforts to support local businesses and community transitions.
Well below national median
Below-average climate & terrain
Housing looks undervalued at 3.2x — home prices are low relative to local economic output. The typical U.S. county is 4–6x.
Estimated local headcount ranges. Larger employers shown as floor + "+"; smaller employers show exact counts where reported.
Source: Redfin · Census BPS — Browse sales on Redfin →
Source: CDC/NCHS vital statistics via County Health Rankings (2020–2022 avg). Rates per 100,000 population. Grade based on homicide rate relative to national average (~6.3). Learn more →
| PROJECT | AMOUNT | STATUS |
|---|---|---|
|
IDOT Highway and Multimodal Multi-Year Program (FY2025-2029)
Illinois Department of Transportation (IDOT)
|
$1,422M | Planned |
|
Cloverleaf Infrastructure Data Center Network (Metro East)
Cloverleaf Infrastructure
|
$500M | Proposed |
|
Bee Hollow Solar Project
Geronimo Power
|
$150M | Under Construction |
|
Herzog Battery Storage Project
Undisclosed (MISO interconnection queue)
|
$150M | Planned |
|
I-255 Resurfacing, Bridge and Ramp Repairs
Illinois Department of Transportation (IDOT)
|
$74M | Planned |
|
I-64 Widening, Resurfacing, Interchange Improvements and Bridge Repairs
Illinois Department of Transportation (IDOT)
|
$52M | Planned |
Source: public records, news, corporate announcements. Amounts are estimates where noted.
Bars show percentile rank among all 996 counties.
With a Boom Town Index score of 65/100, St. Clair County sits in the upper half of all 996 ranked counties. and median household income stands at $68,915 — indicators that suggest solid fundamentals even if it's not among the fastest-growing counties in IL.
By national standards, St. Clair County is quite affordable. Homes here have a median value of $158,500, and the income-to-home-value ratio of 0.43 is well above the U.S. average — especially with median rent at just $1,002/month. Residents can generally buy a home without being cost-burdened.
St. Clair County is losing population (-0.7% YoY) while the job market is essentially flat (-0.1% employment change). Home values are +4.5% over the past 12 months. A slow-bleed pattern — not a collapse, but residents are leaving faster than employers are hiring.
Not particularly — 1.79% of St. Clair County's population moved in from another state, which is below the national average. Most residents are long-term locals rather than recent transplants.