14 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Attica township | 1 | 8,553 | 7,447 | 2.68% | 311 | 27.46 | Township |
| Anthony | 2 | 2,052 | 2,094 | -0.39% | 637 | 3.22 | City |
| Harper | 3 | 1,300 | 1,310 | -0.15% | 801 | 1.62 | City |
| Township 1 | 4 | 840 | 837 | 0.6% | 5 | 180.81 | Township |
| Attica | 5 | 504 | 513 | -0.4% | 795 | 0.63 | City |
| Township 5 | 6 | 412 | 408 | 0.49% | 4 | 106.45 | Township |
| Township 3 | 7 | 286 | 277 | 1.42% | 2 | 146.06 | Township |
| Township 6 | 8 | 272 | 269 | 0.74% | 3 | 108.16 | Township |
| Township 4 | 9 | 199 | 195 | 1.02% | 2 | 114.69 | Township |
| Harper township | 10 | 133 | 134 | -0.75% | 4 | 35.68 | Township |
| Township 2 | 11 | 85 | 82 | 1.19% | 1 | 140.26 | Township |
| Bluff City | 12 | 47 | 47 | 0% | 93 | 0.51 | City |
| Danville | 13 | 29 | 29 | 0% | 349 | 0.08 | City |
| Waldron | 14 | 9 | 9 | 0% | 29 | 0.31 | City |
Attica township is the largest city in Harper County, with a population of 8,553.
Waldron is the smallest city in Harper County.
There are 14 cities in Harper County, Kansas.