Union County Flag

Union County

State:
Ohio
County Seat:
Marysville

Union County's 2026 population is estimated at 75,633, reflecting a 2.65% growth rate over the past year (World Population Review estimate based on U.S. Census Bureau data). Union County is the 32nd largest county in Ohio. The 2010 population was 52,462 and has grown 44.17% since 2010.

75,633
Total Population
175
Population Density (mi²)
32
Population Rank (State)
2K 2.65%
Annual Population Growth

Union County Population

Demographics

Economics and Income Statistics