Union County Flag

Union County

State:
Ohio
County Seat:
Marysville

Union County's estimated 2026 population is 74,909 with a growth rate of 1.99% in the past year according to the most recent United States census data. Union County is the 34th largest county in Ohio. The 2010 population was 52,462 and has seen a growth of 42.79% since that time.

74,909
Total Population
173
Population Density (mi²)
34
Population Rank (State)
1.5K 1.99%
Annual Population Growth

Union County Population

Demographics

Economics and Income Statistics