Illinois 2020 Census Total Voting-age Population (18yrs and over) By County

According to the data from the US 2020 decennial Census, as at April 2020, the total Voting-age population (18 years and over) of Illinois was 9,999,469, which was 78.05% of the total Illinois population.

Cook County had the highest voting-age population (4,172,402), followed by DuPage County (724,333), and then Lake County (544,037). On the other hand, the 3 counties with low voting-age population were: Hardin County (2,985), Pope County (3,068), and Calhoun County (3,535).

You can also see this information for other states and also for the US by state.

Hover over or click on the counties to see the number and percentage of Illinois population that lives in each county. The data can also be found in a table below. You can use the table to sort, filter, and explore the data further.

You can also see the voting-age population by county for the different racial groups as well as the different ethnicities in Illinois.