About DeKalb County
DeKalb County is a city located in United States, in the Illinois region. According to the latest available data (2026), the population of DeKalb County is approximately 100,420 residents, making it the #863 most populous city in United States.
Globally, DeKalb County ranks #15,590 among the world's most populated cities.
DeKalb County City Statistics
| City | DeKalb County |
| Country |  United States |
| Population | 100,420 |
| Global Rank | #15,590 |
| Rank in United States | #863 of 867 cities |
| City Category | city |
| Region | Illinois |
| Latitude | 41.89 |
| Longitude | -88.77 |
| Data Year | 2026 |
Where is DeKalb County Located?
DeKalb County is located in United States, in the Illinois region, at coordinates 41.89° latitude and -88.77° longitude. Located in the mid-latitudes, DeKalb County experiences distinct four-season weather patterns.
Nearby Cities
Other Cities in United States
Largest Cities in United States
| # | City | Population |
|---|---|---|
| 1 | Harris County | 4,731,145 |
| 2 | Los Angeles | 3,898,747 |
| 3 | San Diego County | 3,298,634 |
| 4 | Brooklyn | 2,736,074 |
| 5 | Miami-Dade County | 2,701,767 |
Frequently Asked Questions
What is the population of DeKalb County?
The population of DeKalb County is approximately 100,420 residents according to the latest available data (2026).
Where is DeKalb County located?
DeKalb County is located in United States at approximately 41.89° latitude and -88.77° longitude.
Is DeKalb County one of the largest cities in United States?
With a population of 100,420, DeKalb County is one of the notable urban areas in United States. It ranks #863 out of 867 cities in the country.
