Seneca township is located in Noble County, Ohio. Seneca township has a 2026 population of 409. Seneca township is currently declining at a rate of -0.49% annually and its population has decreased 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.
Data after 2023 is projected based on recent change
Overall: 35.8 years
Female: 25.9 years
Male: 55.3 years
There are 319 adults, (137 of whom are seniors) in Seneca township.
Female: 201 (42%)
Male: 278 (58%)
The racial composition of Seneca township includes 95.82% White, and smaller percentages for and multiracial populations.
| Race | Population ↓ | Percentage (of total) |
|---|---|---|
| White | 459 | 95.82% |
| Two or more races | 20 | 4.18% |