Data / Population / Warren County

Population in Warren County

Population in Warren County was 16,222 in 2025, according to the U.S. Census Bureau. That is up 0.7% from 2024. That is the 65th highest of 102 counties in 2025.

2025, persons16,222
Change on 2024+0.7%
Rank65th of 102Counties in Illinois ranked
Series high16,8372020
Series low16,1162024

Population in Warren County, 2020 to 2025

CSVChart (SVG)

16K16.2K16.4K16.6K16.8K17K2020202120222023202420252020: 16,837 persons2021: 16,622 persons2022: 16,278 persons2023: 16,159 persons2024: 16,116 persons2025: 16,222 persons
persons. Source: U.S. Census Bureau. Retrieved 2026-10-08, published 2026-03-26.
All 6 values
Periodpersons
202516,222
202416,116
202316,159
202216,278
202116,622
202016,837

Compared with Illinois and United States

Place2025
Warren County16,222
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.

Use this data in your AI agent

Invokely serves this figure to AI assistants through MCP and to code through a REST API, with the source and citation attached. Ask your assistant:

What is the latest population in Warren County? Cite the source.
get_value {"indicator":"population","place":"us-county-17187"}
GET https://invokely.ai/api/v1/value?indicator=population&place=us-county-17187

Connect Claude, ChatGPT or Cursor in one step. The trial answers 25 calls a day without an account.

Questions

What is the population in Warren County?

Population in Warren County was 16,222 in 2025, according to the U.S. Census Bureau. That is up 0.7% from 2024. That is the 65th 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 Warren County?

16,837 in 2020, the highest value since 2020 in this series.

More statistics for Warren County

All statistics for Warren County