
Union township
- County:
- Mercer County
- County Seat:
- No
- Area (mi²):
- 36.38
- State:
- Ohio
Union township is located in Mercer County, Ohio. Union township has a 2025 population of 1,334. Union township is currently declining at a rate of -0.15% annually and its population has decreased by -1.62% since the most recent census, which recorded a population of 1,356 in 2020.
The average household income in Union township is $51,372 with a poverty rate of 13.38%. The median age in Union township is 48.3 years: 45.3 years for males, and 54.4 years for females.