5 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Randolph township | 1 | 4,211 | 4,296 | -1.57% | 113 | 37.34 | Township |
| Rising Sun | 2 | 2,227 | 2,229 | 0% | 1,483 | 1.50 | City |
| Cass township | 3 | 684 | 695 | -1.58% | 37 | 18.54 | Township |
| Pike township | 4 | 475 | 482 | -1.66% | 25 | 18.75 | Township |
| Union township | 5 | 448 | 455 | -1.54% | 39 | 11.52 | Township |
Randolph township is the largest city in Ohio County, with a population of 4,211.
Union township is the smallest city in Ohio County.
There are 5 cities in Ohio County, Indiana.