Washington township
- County:
- Mercer County
- County Seat:
- No
- Area (mi²):
- 36.335
- State:
- Ohio
Washington township is located in Mercer County, Ohio. Washington township has a 2026 population of 1,258. Washington township is currently growing at a rate of 1.37% annually and its population has increased by 2.86% since the most recent census, which recorded a population of 1,223 in 2020.
The median household income in Washington township is $96,016 with a poverty rate of 6.09%. The median age in Washington township is 39.5 years: 39.3 years for males, and 42.3 years for females. For every 100 females there are 99.3 males.