8 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Port Clinton | 1 | 5,864 | 6,016 | -0.42% | 2,752 | 2 | City |
| Oak Harbor | 2 | 2,775 | 2,819 | -0.25% | 1,749 | 2 | Village |
| Genoa | 3 | 2,167 | 2,224 | -0.41% | 1,085 | 2 | Village |
| Elmore | 4 | 1,357 | 1,399 | -0.51% | 1,467 | 1 | Village |
| Marblehead | 5 | 828 | 849 | -0.36% | 261 | 3 | Village |
| Rocky Ridge | 6 | 304 | 310 | -0.33% | 303 | 1 | Village |
| Clay Center | 7 | 242 | 259 | -1.22% | 239 | 1 | Village |
| Put-in-Bay | 8 | 150 | 155 | -0.66% | 342 | 0 | Village |
Port Clinton is the largest city in Ottawa County, with a population of 5,864.
Put-in-Bay is the smallest city in Ottawa County, with a population of 150.
There are 8 cities in Ottawa County, Ohio.