In 2018, St. Clair County, IL had a population of 261k people with a median age of 39.6 and a median household income of $59,141. Between 2017 and 2018 the population of St. Clair County, IL declined from 262,479 to 261,059, a -0.541% decrease and its median household income grew from $51,670 to $59,141, a 14.5% increase.
N/A NaNk% of the people in St. Clair County, IL speak a non-English language, and 98.1% are U.S. citizens.
The largest universities in St. Clair County, IL are Southwestern Illinois College (2,672 degrees awarded in 2017), McKendree University (830 degrees), and Vatterott College-Fairview Heights (143 degrees).
The median property value in St. Clair County, IL is $132,200, and the homeownership rate is 65.8%. Most people in St. Clair County, IL commute by Drove Alone, and the average commute time is 24.5 minutes. The average car ownership in St. Clair County, IL is 2 cars per household.
St. Clair County, IL borders Clinton County, IL, Monroe County, IL, Randolph County, IL, Washington County, IL, St. Louis County, MO, St. Louis city, MO, and Madison County, IL.