As of 2026 the population of St. Clair County is 9,803. The population is expected to grow to 10,026 by 2031 - a growth rate of 0.45%.
The median age of St. Clair County residents is 48.
The diversity index of St. Clair County is 18.3, meaning that there is a 18% chance that any two people selected out of 100 residents will be of different race or ethnicity from one another.
The average household income in St. Clair County is $66,063 and projected to be $72,346 in 2031. Per capita income is $28,230, projected to be $31,011 in 2031. 1% of households – 98 – have an income of $200,000 or higher. Average net worth is $647,688 and the average disposable income is $52,517.
There are 5,579 housing units in St. Clair County; 3,176 are owner-occupied, 992 are rented, and 1,411 are vacant. The average home value is $306,791, with 427 homes built in 2010 or later, and 729 built in 1939 or earlier.
There are 302 businesses in St. Clair County, employing 2,521 workers and pulling from a labor force of 3,894 age 16 and above. 1,756 workers commute into St. Clair County from outside the county or state. Key industries for the area include:
1,950 residents both live and work in/around St. Clair County. The average travel time is 28.4 minutes. 11.28% people have a commute of less than 5 minutes while 11.03% commute 90 minutes or more each way. Of commuters, 2,939 drive alone, 532 carpool, and 8 take public transportation. 71 use other modes of transport such as motorcycle, bicycle, walking, etc. 344 residents work from home.
3,068 members of the workforce hold a high school diploma or GED. 712 have associates degrees, 780 have bachelor’s degrees, and 353 hold a graduate or professional degree.
Source: ESRI, 2026-09-09
