Marion city, Illinois Demographics & Population 2026

Population Overview

Marion city is a small city located in Illinois. The total population is 16,796. It ranks as the 150th most populous out of 1,445 cities and towns in Illinois.

Age Demographics

The median age in Marion city is 40.4 years. This is 4% higher than the state median of 38.9 years.

Economy, Income & Housing

The median household income in Marion city is $57,281. This is 30% lower than the state median of $81,702. Compared to the national median of $78,538, household income here is 27% lower. The poverty rate stands at 16.0%. This is 36% higher than the state poverty rate of 11.7%. The unemployment rate is 4.0%. This is 30% lower than the state rate of 5.8%. The median home value is $145,300. Housing costs are 42% lower than the state median of $250,500. With a home-value-to-income ratio of just 2.5x, Marion city is one of the most affordable housing markets in the area. 62.2% of occupied housing units are owner-occupied. This homeownership rate is 7% lower than the state average of 66.8%.

Race & Ethnicity

Marion city has a predominantly White (non-Hispanic) population, comprising 85.1% of all residents. Black or African American residents account for 5.1%. The Black or African American population (5.1%) is well below the state average of 13.6%. The Hispanic or Latino population (3.7%) is well below the state average of 18.5%. The Asian population (2.8%) is well below the state average of 5.8%.

Education

27.4% of residents aged 25 and older hold a bachelor's degree or higher. This is 26% 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 93.8%.

Data Sources & Methodology

All demographic data for Marion city, Illinois is sourced from the U.S. Census Bureau's American Community Survey (ACS) 5-Year Estimates (2019-2023). The ACS collects data from approximately 3.5 million households annually, providing reliable estimates for communities of all sizes. Comparisons are made against Illinois state averages and national averages calculated from the same dataset. Rankings reflect the city's position among all 1,445 Census-designated places in Illinois. For official data, visit data.census.gov.