Mercer County Flag

Mercer County

State:
Illinois
County Seat:
Aledo

Mercer County's estimated 2025 population is 15,128 with a growth rate of -1.07% in the past year according to the most recent United States census data. Mercer County is the 70th largest county in Illinois. The 2010 population was 16,410 and has seen a growth of -7.81% since that time.

15,128
Total Population
27
Population Density (mi²)
70
Population Rank (State)
-164 -1.07%
Annual Population Growth

Mercer County Population

Demographics

Economics and Income Statistics

Sources

  1. City and Town Population Totals: 2020-2024
  2. US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
  3. US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
  4. American Community Survey (2009 - 2013)
  5. Census QuickFacts
  6. Historical Populations of States and Counties (1790 - 1990)