| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| East Grand Forks | 1 | 8,857 | 9,157 | -0.55% | 1,490 | 6 | City |
| Crookston | 2 | 7,360 | 7,482 | -0.2% | 1,439 | 5 | City |
| Fosston | 3 | 1,372 | 1,434 | -0.8% | 685 | 2 | City |
| Fertile | 4 | 773 | 797 | -0.51% | 372 | 2 | City |
| McIntosh | 5 | 572 | 600 | -0.87% | 573 | 1 | City |
| Fisher | 6 | 398 | 419 | -1% | 934 | 0 | City |
| Erskine | 7 | 380 | 401 | -1.04% | 589 | 1 | City |
| Climax | 8 | 239 | 242 | -0.42% | 255 | 1 | City |
| Winger | 9 | 177 | 179 | -0.56% | 546 | 0 | City |
| Mentor | 10 | 106 | 111 | -0.93% | 56 | 2 | City |
| Beltrami | 11 | 85 | 90 | -1.16% | 43 | 2 | City |
| Nielsville | 12 | 75 | 77 | -1.32% | 349 | 0 | City |
| Gully | 13 | 55 | 56 | 0% | 224 | 0 | City |
| Trail | 14 | 38 | 38 | 0% | 38 | 1 | City |
East Grand Forks is the largest city in Polk County, with a population of 8,857.
Trail is the smallest city in Polk County, with a population of 38.
There are 14 cities in Polk County, Minnesota.