20 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Trotwood | 1 | 23,070 | 23,079 | 0% | 757 | 30 | City |
| Greenville | 2 | 12,649 | 12,805 | -0.21% | 1,902 | 7 | City |
| Versailles | 3 | 2,705 | 2,746 | -0.26% | 1,347 | 2 | Village |
| Arcanum | 4 | 2,321 | 2,356 | -0.26% | 1,825 | 1 | Village |
| Union City | 5 | 1,557 | 1,578 | -0.19% | 1,696 | 1 | Village |
| Ansonia | 6 | 1,145 | 1,156 | -0.17% | 1,770 | 1 | Village |
| New Madison | 7 | 830 | 842 | -0.24% | 1,751 | 0 | Village |
| Wayne Lakes | 8 | 682 | 688 | -0.15% | 1,284 | 1 | Village |
| Gettysburg | 9 | 460 | 465 | -0.22% | 1,050 | 0 | Village |
| Pitsburg | 10 | 374 | 382 | -0.27% | 2,213 | 0 | Village |
| Osgood | 11 | 297 | 306 | -0.34% | 844 | 0 | Village |
| Hollansburg | 12 | 238 | 246 | -0.42% | 1,967 | 0 | Village |
| Gordon | 13 | 227 | 235 | -0.44% | 1,376 | 0 | Village |
| North Star | 14 | 225 | 230 | -0.44% | 439 | 1 | Village |
| Palestine | 15 | 177 | 183 | -0.56% | 1,212 | 0 | Village |
| Rossburg | 16 | 158 | 161 | 0% | 1,129 | 0 | Village |
| New Weston | 17 | 123 | 125 | 0% | 480 | 0 | Village |
| Castine | 18 | 105 | 107 | 0% | 1,382 | 0 | Village |
| Yorkshire | 19 | 103 | 105 | 0% | 381 | 0 | Village |
| Ithaca | 20 | 91 | 93 | 0% | 2,935 | 0 | Village |
Trotwood is the largest city in Darke County, with a population of 23,070.
Ithaca is the smallest city in Darke County, with a population of 91.
There are 20 cities in Darke County, Ohio.