33 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Trotwood | 1 | 22,849 | 23,076 | -0.2% | 749 | 30 | City |
| Greenville | 2 | 16,962 | 17,185 | -0.21% | 296 | 57 | Township |
| Greenville | 3 | 12,623 | 12,805 | -0.28% | 1,898 | 7 | City |
| Twin | 4 | 4,176 | 4,235 | -0.19% | 144 | 29 | Township |
| Adams | 5 | 3,281 | 3,340 | -0.33% | 88 | 37 | Township |
| Versailles | 6 | 2,696 | 2,741 | -0.33% | 1,343 | 2 | Village |
| Arcanum | 7 | 2,312 | 2,352 | -0.34% | 1,818 | 1 | Village |
| Neave | 8 | 2,180 | 2,198 | -0.09% | 95 | 23 | Township |
| Brown | 9 | 2,021 | 2,046 | -0.2% | 68 | 30 | Township |
| Union City | 10 | 1,554 | 1,579 | -0.32% | 1,693 | 1 | Village |
| Patterson | 11 | 1,414 | 1,440 | -0.28% | 53 | 27 | Township |
| Washington | 12 | 1,256 | 1,276 | -0.32% | 40 | 32 | Township |
| Ansonia | 13 | 1,143 | 1,157 | -0.26% | 1,767 | 1 | Village |
| Allen | 14 | 995 | 1,004 | -0.2% | 35 | 29 | Township |
| Liberty | 15 | 974 | 988 | -0.2% | 29 | 33 | Township |
| Wabash | 16 | 912 | 927 | -0.33% | 42 | 22 | Township |
| Richland | 17 | 835 | 827 | 0.36% | 40 | 21 | Township |
| New Madison | 18 | 822 | 841 | -0.48% | 1,734 | 0 | Village |
| Wayne Lakes | 19 | 682 | 694 | -0.29% | 1,284 | 1 | Village |
| Mississinawa | 20 | 676 | 686 | -0.29% | 23 | 29 | Township |
| York | 21 | 555 | 564 | -0.18% | 26 | 22 | Township |
| Gettysburg | 22 | 458 | 465 | -0.22% | 1,046 | 0 | Village |
| Pitsburg | 23 | 376 | 385 | -0.53% | 2,225 | 0 | Village |
| Osgood | 24 | 294 | 306 | -0.68% | 835 | 0 | Village |
| Gordon | 25 | 236 | 241 | -0.42% | 1,430 | 0 | Village |
| Hollansburg | 26 | 235 | 244 | -0.84% | 1,942 | 0 | Village |
| North Star | 27 | 220 | 225 | -0.45% | 430 | 1 | Village |
| Palestine | 28 | 178 | 182 | -0.56% | 1,219 | 0 | Village |
| Rossburg | 29 | 155 | 159 | -0.64% | 1,107 | 0 | Village |
| New Weston | 30 | 120 | 124 | -0.83% | 469 | 0 | Village |
| Castine | 31 | 106 | 108 | 0% | 1,395 | 0 | Village |
| Yorkshire | 32 | 103 | 105 | 0% | 381 | 0 | Village |
| Ithaca | 33 | 84 | 86 | 0% | 2,710 | 0 | Village |
Trotwood is the largest city in Darke County, with a population of 22,849.
Ithaca is the smallest city in Darke County, with a population of 84.
There are 33 cities in Darke County, Ohio.