Data / Population / Union County

Population in Union County

Population in Union County was 16,656 in 2025, according to the U.S. Census Bureau. That is down 1% from 2024. That is the 63rd highest of 102 counties in 2025.

2025, persons16,656
Change on 2024-1%
Rank63rd of 102Counties in Illinois ranked
Series high17,2992020
Series low16,6562025

Population in Union County, 2020 to 2025

CSVChart (SVG)

16.6K16.8K17K17.2K17.4K2020202120222023202420252020: 17,299 persons2021: 17,049 persons2022: 16,916 persons2023: 16,865 persons2024: 16,832 persons2025: 16,656 persons
persons. Source: U.S. Census Bureau. Retrieved 2026-10-08, published 2026-03-26.
All 6 values
Periodpersons
202516,656
202416,832
202316,865
202216,916
202117,049
202017,299

Compared with Illinois and United States

Place2025
Union County16,656
Illinois12,719,141
United States341,784,857

Rankings

Definition

Resident population. Spain and the EU: 1 January, with Spanish figures from the official municipal register (Padrón). United States: Census Bureau population estimates for 1 July. Other countries and the World: World Bank mid-year estimates, which count all residents regardless of legal status or citizenship.

For Denmark, Statistics Denmark counts the registered resident population on 1 January. Greenland and the Faroe Islands are excluded. The annual series selects the first-quarter reference date from FOLK1A. The World Bank series exists for every country, so use it (through compare) to rank countries on one basis.

How to cite

U.S. Census Bureau. Annual estimates of the resident population for the United States, states and counties, 1 July (Population Estimates Program). https://www2.census.gov/programs-surveys/popest/datasets/2020-2025/. Retrieved 2026-10-08.

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What is the latest population in Union County? Cite the source.
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Questions

What is the population in Union County?

Population in Union County was 16,656 in 2025, according to the U.S. Census Bureau. That is down 1% from 2024. That is the 63rd highest of 102 counties in 2025.

Where does this figure come from?

U.S. Census Bureau. Annual estimates of the resident population for the United States, states and counties, 1 July (Population Estimates Program). Retrieved by Invokely on 2026-10-08.

What was the highest population in Union County?

17,299 in 2020, the highest value since 2020 in this series.

More statistics for Union County

All statistics for Union County