Mason County Flag

Mason County

State:
Illinois
County Seat:
Havana

Mason County's estimated 2026 population is 12,453 with a growth rate of -0.36% in the past year according to the most recent United States census data. Mason County is the 82nd largest county in Illinois. The 2010 population was 14,651 and has seen a growth of -15% since that time.

12,453
Total Population
23
Population Density (mi²)
82
Population Rank (State)
-45 -0.36%
Annual Population Growth

Mason County Population

Demographics

Economics and Income Statistics