St. Clair County, MO Demographics
St. Clair County, MO is the 89th most populous of 115 counties in Missouri, with 9,284 residents across 675 square miles. That is about 14 people per square mile.
At the 2020 census
| Population | 9,284 |
|---|---|
| Land area | 675 sq mi |
| Density | 14 / sq mi |
Data: 2020 Census · American Community Survey 2024
How St. Clair County compares to the US
We're computing this county's comparison table — check back shortly. Population, land area, and density above are already exact.
Central Location: St. Clair County, MO
Measured from the county's main population center using 2020 census blocks.
We're computing the drive-time and radius areas around St. Clair County, MO — check back shortly. Meanwhile you can drop a pin anywhere in the radius tool.
Census tracts in St. Clair County, MO
| Name | Population | Sq mi | Per sq mi |
|---|---|---|---|
| Census Tract 4801 | 3,529 | 196.0 | 18 |
| Census Tract 4803 | 3,043 | 170.1 | 18 |
| Census Tract 4802 | 2,712 | 308.9 | 9 |
Related places
About this page
This page shows demographics for a US county from the 2020 census and the American Community Survey: population, land area, density, urban share, and how the county compares to national averages for income, housing, age, and more.
Counties subdivide into census tracts, listed below with their populations. The drive-time and radius tables measure the population around the county's main population center.