In 2020, St. Clair County, IL had a population of 261k people with a median age of 39.1 and a median household income of $57,473. Between 2019 and 2020 the population of St. Clair County, IL declined from 262,338 to 261,186, a −0.439% decrease and its median household income grew from $55,179 to $57,473, a 4.16% increase.
The 5 largest ethnic groups in St. Clair County, IL are White (Non-Hispanic) (61%), Black or African American (Non-Hispanic) (29.7%), Two+ (Non-Hispanic) (3.09%), White (Hispanic) (2.16%), and Asian (Non-Hispanic) (1.42%).
None of the households in St. Clair County, IL reported speaking a non-English language at home as their primary shared language. This does not consider the potential multi-lingual nature of households, but only the primary self-reported language spoken by all members of the household.
98.5% of the residents in St. Clair County, IL are U.S. citizens.
In 2020, the median property value in St. Clair County, IL was $134,800, and the homeownership rate was 65.9%.
Most people in St. Clair County, IL drove alone to work, and the average commute time was 25.4 minutes. The average car ownership in St. Clair County, IL was 2 cars per household.