Rock Island County, Illinois Demographics 2026

Population Overview

Rock Island County is located in Illinois with a total population of 142,995. It is the 14th most populous county out of 102 in Illinois.

Age Demographics

The median age in Rock Island County is 40.3 years. This is 4% higher than the state median of 38.9 years.

Economy, Income & Housing

The median household income in Rock Island County is $66,768. This is 18% lower than the state median of $81,702. Compared to the national median of $78,538, household income here is 15% lower. The poverty rate stands at 15.4%. This is 31% higher than the state poverty rate of 11.7%. The unemployment rate is 5.7%. This is 1% lower than the state rate of 5.8%. The median home value is $144,700. Housing costs are 42% lower than the state median of $250,500. With a home-value-to-income ratio of just 2.2x, Rock Island County is one of the most affordable housing markets in the area. 68.6% of occupied housing units are owner-occupied. This homeownership rate is 3% higher than the state average of 66.8%.

Race & Ethnicity

The largest racial or ethnic group in Rock Island County is White (non-Hispanic), making up 68.5% of the population. Hispanic or Latino residents account for 14.0%. The Asian population (2.5%) is well below the state average of 5.8%.

Education

24.1% of residents aged 25 and older hold a bachelor's degree or higher. This is 35% 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 90.2%.