| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Trotwood | 1 | 23,188 | 23,069 | -0.01% | 761 | 30 | City |
| Greenville | 2 | 12,643 | 12,803 | -0.29% | 1,901 | 7 | City |
| Versailles | 3 | 2,712 | 2,743 | -0.4% | 1,351 | 2 | Village |
| Arcanum | 4 | 2,322 | 2,343 | -0.21% | 1,825 | 1 | Village |
| Union City | 5 | 1,563 | 1,578 | -0.26% | 1,703 | 1 | Village |
| Ansonia | 6 | 1,145 | 1,152 | -0.17% | 1,770 | 1 | Village |
| New Madison | 7 | 828 | 841 | -0.36% | 1,747 | 0 | Village |
| Wayne Lakes | 8 | 684 | 689 | -0.15% | 1,288 | 1 | Village |
| Gettysburg | 9 | 462 | 466 | -0.22% | 1,055 | 0 | Village |
| Pitsburg | 10 | 375 | 382 | -0.53% | 2,219 | 0 | Village |
| Osgood | 11 | 300 | 308 | -0.66% | 852 | 0 | Village |
| Hollansburg | 12 | 241 | 245 | -0.41% | 1,992 | 0 | Village |
| Gordon | 13 | 238 | 244 | -0.42% | 1,442 | 0 | Village |
| North Star | 14 | 228 | 229 | -0.44% | 445 | 1 | Village |
| Palestine | 15 | 179 | 184 | -0.56% | 1,226 | 0 | Village |
| Rossburg | 16 | 161 | 161 | 0% | 1,150 | 0 | Village |
| New Weston | 17 | 120 | 123 | -0.83% | 469 | 0 | Village |
| Yorkshire | 18 | 104 | 106 | -0.95% | 385 | 0 | Village |
| Castine | 19 | 100 | 102 | -0.99% | 1,316 | 0 | Village |
| Ithaca | 20 | 98 | 100 | -1.01% | 3,161 | 0 | Village |
Trotwood is the largest city in Darke County, with a population of 23,188.
Ithaca is the smallest city in Darke County, with a population of 98.
There are 20 cities in Darke County, Ohio.