Union County, Illinois Demographics 2026

Population Overview

Union County is located in Illinois with a total population of 16,997. It is the 61st most populous county out of 102 in Illinois. The county encompasses 6 Census-designated places.

Age Demographics

The median age in Union County is 44.3 years. This is 14% higher than the state median of 39.0 years. 10.4% of residents are 75 or older, suggesting a significant retirement-age population with implications for healthcare services and senior housing.

Economy, Income & Housing

The median household income in Union County is $55,728. This is 33% lower than the state median of $83,390. It is also 31% lower than the national median of $80,734. The poverty rate stands at 20.2%. This is 71% higher than the state poverty rate of 11.8%. With more than one in five residents living below the poverty line, economic hardship is a significant challenge for the community. The unemployment rate is 3.9%. This is 33% lower than the state rate of 5.8%. The median home value is $131,700. Housing costs are 50% lower than the state median of $263,300. With a home-value-to-income ratio of just 2.4x, Union County is one of the most affordable housing markets in the area. 77.5% of occupied housing units are owner-occupied. This homeownership rate is 15% higher than the state average of 67.1%.

Race & Ethnicity

Union County has a predominantly White (non-Hispanic) population, comprising 89.5% of all residents. Hispanic or Latino residents account for 5.5%. The White (non-Hispanic) population is significantly higher than the state average (89.5% vs 58.1%). The Black or African American population (0.9%) is well below the state average of 13.3%. The Hispanic or Latino population (5.5%) is well below the state average of 18.8%. The Asian population (0.6%) is well below the state average of 5.9%.

Education

20.9% of residents aged 25 and older hold a bachelor's degree or higher. This is 45% lower than the state rate of 37.9%. Nationally, 35.7% of adults hold at least a bachelor's degree. The high school graduation rate (or equivalent) is 87.5%.

Data Sources & Methodology

All figures for Union County come from the U.S. Census Bureau's American Community Survey (ACS) 2020–2024 5-Year Estimates, with comparisons drawn against Illinois and national averages from the same dataset. See our methodology page for how each metric is defined, or data.census.gov for official tables with margins of error.