33 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 | 17,062 | 17,185 | 0.05% | 298 | 57 | Township |
| Greenville | 3 | 12,649 | 12,805 | -0.21% | 1,902 | 7 | City |
| Twin | 4 | 4,200 | 4,239 | 0.02% | 145 | 29 | Township |
| Adams | 5 | 3,316 | 3,345 | 0.06% | 89 | 37 | Township |
| Versailles | 6 | 2,705 | 2,746 | -0.26% | 1,347 | 2 | Village |
| Arcanum | 7 | 2,321 | 2,356 | -0.26% | 1,825 | 1 | Village |
| Neave | 8 | 2,202 | 2,197 | 0.27% | 96 | 23 | Township |
| Brown | 9 | 2,037 | 2,046 | 0.1% | 69 | 30 | Township |
| Union City | 10 | 1,557 | 1,578 | -0.19% | 1,696 | 1 | Village |
| Patterson | 11 | 1,420 | 1,434 | 0.07% | 53 | 27 | Township |
| Washington | 12 | 1,266 | 1,277 | 0% | 40 | 32 | Township |
| Ansonia | 13 | 1,145 | 1,156 | -0.17% | 1,770 | 1 | Village |
| Allen | 14 | 1,003 | 1,005 | 0.1% | 35 | 29 | Township |
| Liberty | 15 | 981 | 988 | 0.1% | 30 | 33 | Township |
| Wabash | 16 | 919 | 928 | 0% | 42 | 22 | Township |
| New Madison | 17 | 830 | 842 | -0.24% | 1,751 | 0 | Village |
| Richland | 18 | 829 | 832 | 0% | 39 | 21 | Township |
| Mississinawa | 19 | 685 | 686 | 0.15% | 23 | 29 | Township |
| Wayne Lakes | 20 | 682 | 688 | -0.15% | 1,284 | 1 | Village |
| York | 21 | 557 | 564 | 0% | 26 | 22 | Township |
| Gettysburg | 22 | 460 | 465 | -0.22% | 1,050 | 0 | Village |
| Pitsburg | 23 | 374 | 382 | -0.27% | 2,213 | 0 | Village |
| Osgood | 24 | 297 | 306 | -0.34% | 844 | 0 | Village |
| Hollansburg | 25 | 238 | 246 | -0.42% | 1,967 | 0 | Village |
| Gordon | 26 | 227 | 235 | -0.44% | 1,376 | 0 | Village |
| North Star | 27 | 225 | 230 | -0.44% | 439 | 1 | Village |
| Palestine | 28 | 177 | 183 | -0.56% | 1,212 | 0 | Village |
| Rossburg | 29 | 158 | 161 | 0% | 1,129 | 0 | Village |
| New Weston | 30 | 123 | 125 | 0% | 480 | 0 | Village |
| Castine | 31 | 105 | 107 | 0% | 1,382 | 0 | Village |
| Yorkshire | 32 | 103 | 105 | 0% | 381 | 0 | Village |
| Ithaca | 33 | 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 33 cities in Darke County, Ohio.