Observations

2025: 5,194.625

Updated: Mar 27, 2026 2:57 PM CDT

Units:

Thousands of Persons,

Not Seasonally Adjusted

Frequency:

Annual

Notes

Title	Release Dates

Resident Population in Cook County, IL	2007-03-22	2026-03-26

Source

U.S. Census Bureau	2007-03-22	2026-03-26

Release

Annual Estimates of the Population for Counties	2007-03-22	2026-03-26

Units

Thousands of Persons	2007-03-22	2026-03-26

Frequency

Annual	2007-03-22	2026-03-26

Seasonal Adjustment

Not Seasonally Adjusted	2007-03-22	2026-03-26

Notes

Data for "Resident Population" are estimates as of July 1. Data for 1970, 1980, 1990, and 2000 are annual census. Population estimates are updated annually using current data on births, deaths, and migration to calculate population change since the most recent decennial census. The annual time series of estimates begins with the most recent decennial census data and extends to the vintage year. Each vintage of estimates includes all years since the most recent decennial census.	2007-03-22	2026-03-26

Release Tables

Annual Estimates of the Population for Counties