St. Louis, MO-IL Metro Area
The St. Louis, MO-IL metro area is made up of 15 counties and independent cities in Missouri and Illinois; the largest are St. Louis County, St. Charles County, and St. Louis city. About 2,814,421 people lived there on July 1, 2025 (Census estimate), 0.2% fewer than in April 2020.
- Population, July 2025
- 2,814,421 0.2% fewer than in April 2020
- Type
- Metropolitan statistical area
- Counties and independent cities
- 15: 7 central, 8 outlying
- Land area
- 7,863 sq mi (20,366 km²)
- Time zone
- Central TimeUTC-06:00 in January; UTC-05:00 in July
- Combined statistical area
- St. Louis-St. Charles-Farmington, MO-IL
- CBSA code
- 41180
Counties and independent cities in the St. Louis, MO-IL metro area, largest first
| County or independent city | Role | Population, July 2025 | Share of the area |
|---|---|---|---|
| St. Louis CountyMissouri | Central | 990,911 | 35.2% |
| St. Charles CountyMissouri | Central | 426,499 | 15.2% |
| St. Louis cityMissouri | Central | 278,144 | 9.9% |
| Madison CountyIllinois | Central | 263,110 | 9.3% |
| St. Clair CountyIllinois | Central | 250,708 | 8.9% |
| Jefferson CountyMissouri | Central | 233,132 | 8.3% |
| Franklin CountyMissouri | Outlying | 108,090 | 3.8% |
| Lincoln CountyMissouri | Outlying | 66,676 | 2.4% |
| Macoupin CountyIllinois | Outlying | 43,748 | 1.6% |
| Warren CountyMissouri | Outlying | 39,016 | 1.4% |
| Clinton CountyIllinois | Outlying | 37,128 | 1.3% |
| Monroe CountyIllinois | Central | 34,840 | 1.2% |
| Jersey CountyIllinois | Outlying | 21,160 | 0.8% |
| Bond CountyIllinois | Outlying | 16,959 | 0.6% |
| Calhoun CountyIllinois | Outlying | 4,300 | 0.2% |
A central county or independent city holds the area’s core, an urban area of at least 50,000 people. An outlying county or independent city is in the area because of commuting: at least a quarter of its workers have jobs in the central counties and independent cities, or at least a quarter of the people working there live in them. A county or independent city belongs to one metro or micro area at most, and it counts whole, countryside included.
Principal cities, largest first
- St. Louis288,512 people
- St. Charles71,508 people
OMB names the area after its largest principal cities. A principal city is the area’s largest city, plus any other city that is very large or a big job center, and smaller ones with at least as many jobs as working residents (2020 Census and commuting figures). People counts are American Community Survey 2020–2024 5-year estimates.
Part of the St. Louis-St. Charles-Farmington, MO-IL combined statistical area
OMB joins neighboring metro and micro areas into a combined statistical area when enough people commute between them. The other 2 areas in this one, largest first:
- Farmington, MO Micro Area67,809 people
- Centralia, IL Micro Area36,382 people
Bordering metro and micro areas, nearest first
Areas with a county or independent city on this area’s edge. Distances are straight lines between the areas’ largest cities.
- Farmington, MO Micro Area60 mi south
- Centralia, IL Micro Area61 mi east
- Jacksonville, IL Micro Area76 mi north
- Springfield, IL Metro Area86 mi north
Before using this answer on a form
A metro or micro area is a statistical area that OMB draws for federal statistics. It is not a city, a local government or a mailing address, and it is not a measure of urban and rural: whole counties count, rural parts included. Programs that use metro areas, such as housing income limits or wage rates, can use their own version of these lists; check the program’s own list for an address.
Find the metro area where you are now, find your county, or see every metro and micro area by population.