Seneca township
- County:
- Noble County
- County Seat:
- No
- Area (mi²):
- 23.61
- State:
- Ohio
Seneca township is located in Noble County, Ohio. Seneca township has a 2026 population of 413. Seneca township is currently declining at a rate of -0.48% annually but its population has increased by 0.49% since the most recent census, which recorded a population of 411 in 2020.
The median age in Seneca township is 35.8 years: 55.3 years for males, and 25.9 years for females. For every 100 females there are 138.3 males.