Marion County, Illinois Demographics 2026

Population Overview

Marion County is located in Illinois with a total population of 37,294. It is the 36th most populous county out of 102 in Illinois.

Age Demographics

The median age in Marion County is 41.3 years. This is 6% higher than the state median of 38.9 years.

Economy, Income & Housing

The median household income in Marion County is $60,839. This is 26% lower than the state median of $81,702. Compared to the national median of $78,538, household income here is 23% lower. The poverty rate stands at 16.2%. This is 38% higher than the state poverty rate of 11.7%. The unemployment rate is 6.4%. This is 11% higher than the state rate of 5.8%. The median home value is $100,100. Housing costs are 60% lower than the state median of $250,500. With a home-value-to-income ratio of just 1.6x, Marion County is one of the most affordable housing markets in the area. 74.5% of occupied housing units are owner-occupied. This homeownership rate is 11% higher than the state average of 66.8%.

Race & Ethnicity

Marion County has a predominantly White (non-Hispanic) population, comprising 89.6% of all residents. Black or African American residents account for 4.2%. The White (non-Hispanic) population is significantly higher than the state average (89.6% vs 58.8%). The Black or African American population (4.2%) is well below the state average of 13.6%. The Hispanic or Latino population (2.1%) is well below the state average of 18.5%. The Asian population (0.7%) is well below the state average of 5.8%.

Education

17.3% of residents aged 25 and older hold a bachelor's degree or higher. This is 54% 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 90.3%.