DeKalb County Flag

DeKalb County

State:
Illinois
County Seat:
Clinton

DeKalb County's estimated 2025 population is 100,418 with a growth rate of 0.06% in the past year according to the most recent United States census data. DeKalb County is the 19th largest county in Illinois. The 2010 population was 105,151 and has seen a growth of -4.5% since that time.

100,418
Total Population
159
Population Density (mi²)
19
Population Rank (State)
65 0.06%
Annual Population Growth

DeKalb County Population

Demographics

Economics and Income Statistics