25 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Fargo | 1 | 141,434 | 125,986 | 1.85% | 2,726 | 52 | City |
| West Fargo | 2 | 42,090 | 38,901 | 1.28% | 2,602 | 16 | City |
| Horace | 3 | 7,804 | 3,249 | 10.77% | 616 | 13 | City |
| Casselton | 4 | 2,491 | 2,475 | 0.12% | 1,152 | 2 | City |
| Mapleton | 5 | 1,548 | 1,332 | 2.38% | 396 | 4 | City |
| Kindred | 6 | 1,080 | 930 | 2.37% | 745 | 1 | City |
| Reile's Acres | 7 | 937 | 724 | 4% | 826 | 1 | City |
| Harwood | 8 | 860 | 796 | 1.3% | 660 | 1 | City |
| Argusville | 9 | 473 | 484 | -0.42% | 118 | 4 | City |
| Oxbow | 10 | 373 | 378 | -0.27% | 243 | 2 | City |
| Hunter | 11 | 327 | 335 | -0.3% | 219 | 1 | City |
| Arthur | 12 | 324 | 326 | 0% | 212 | 2 | City |
| Tower City | 13 | 280 | 267 | 0.72% | 137 | 2 | City |
| Davenport | 14 | 250 | 255 | -0.4% | 919 | 0 | City |
| Leonard | 15 | 243 | 248 | -0.41% | 324 | 1 | City |
| Grandin | 16 | 200 | 185 | 1.52% | 1,105 | 0 | City |
| Frontier | 17 | 195 | 198 | 0% | 1,037 | 0 | City |
| Buffalo | 18 | 187 | 193 | -0.53% | 389 | 0 | City |
| Page | 19 | 186 | 192 | -0.53% | 185 | 1 | City |
| Gardner | 20 | 123 | 129 | -0.81% | 247 | 0 | City |
| Amenia | 21 | 87 | 86 | 0% | 58 | 1 | City |
| North River | 22 | 55 | 57 | 0% | 902 | 0 | City |
| Briarwood | 23 | 54 | 54 | 0% | 378 | 0 | City |
| Prairie Rose | 24 | 53 | 55 | 0% | 1,293 | 0 | City |
| Ayr | 25 | 12 | 12 | 0% | 141 | 0 | City |
Fargo is the largest city in Cass County, with a population of 141,434.
Ayr is the smallest city in Cass County, with a population of 12.
There are 25 cities in Cass County, North Dakota.