Clinton County, Illinois Demographics 2026

Population Overview

Clinton County is located in Illinois with a total population of 36,899. It is the 37th most populous county out of 102 in Illinois.

Age Demographics

The median age in Clinton County is 41.4 years. This is 6% higher than the state median of 38.9 years.

Economy, Income & Housing

The median household income in Clinton County is $82,314. This is about average than the state median of $81,702. Compared to the national median of $78,538, household income here is 5% higher. The poverty rate stands at 7.5%. This is 36% lower than the state poverty rate of 11.7%. The unemployment rate is 3.3%. This is 43% lower than the state rate of 5.8%. The median home value is $180,500. Housing costs are 28% lower than the state median of $250,500. With a home-value-to-income ratio of just 2.2x, Clinton County is one of the most affordable housing markets in the area. 79.3% of occupied housing units are owner-occupied. This homeownership rate is 19% higher than the state average of 66.8%.

Race & Ethnicity

Clinton County has a predominantly White (non-Hispanic) population, comprising 90.5% of all residents. Hispanic or Latino residents account for 3.9%. The White (non-Hispanic) population is significantly higher than the state average (90.5% vs 58.8%). The Black or African American population (3.1%) is well below the state average of 13.6%. The Hispanic or Latino population (3.9%) is well below the state average of 18.5%. The Asian population (0.6%) is well below the state average of 5.8%.

Education

24.4% of residents aged 25 and older hold a bachelor's degree or higher. This is 34% lower than the state rate of 37.2%. Nationally, 35.0% of adults hold at least a bachelor's degree. The high school graduation rate (or equivalent) is 92.0%.