Big Island township
- County:
- Marion County
- County Seat:
- No
- Area (mi²):
- 35.249
- State:
- Ohio
Big Island township is located in Marion County, Ohio. Big Island township has a 2026 population of 1,182. Big Island township is currently growing at a rate of 0.17% annually but its population has decreased by -0.76% since the most recent census, which recorded a population of 1,191 in 2020.
The median household income in Big Island township is $43,750 with a poverty rate of 0%. The median age in Big Island township is 69.5 years: 66.2 years for males, and 70.8 years for females. For every 100 females there are 72.0 males.