14 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| East Grand Forks | 1 | 8,798 | 9,148 | -0.65% | 1,480 | 6 | City |
| Crookston | 2 | 7,162 | 7,483 | -0.73% | 1,400 | 5 | City |
| Fosston | 3 | 1,353 | 1,424 | -0.88% | 676 | 2 | City |
| Fertile | 4 | 771 | 798 | -0.52% | 371 | 2 | City |
| McIntosh | 5 | 571 | 601 | -0.87% | 572 | 1 | City |
| Fisher | 6 | 395 | 419 | -1% | 927 | 0 | City |
| Erskine | 7 | 379 | 402 | -1.04% | 588 | 1 | City |
| Climax | 8 | 240 | 243 | 0% | 256 | 1 | City |
| Winger | 9 | 171 | 174 | 0% | 528 | 0 | City |
| Mentor | 10 | 100 | 108 | -0.99% | 52 | 2 | City |
| Beltrami | 11 | 88 | 93 | -1.12% | 44 | 2 | City |
| Nielsville | 12 | 76 | 81 | -1.3% | 353 | 0 | City |
| Gully | 13 | 54 | 56 | 0% | 220 | 0 | City |
| Trail | 14 | 38 | 38 | 0% | 38 | 1 | City |
East Grand Forks is the largest city in Polk County, with a population of 8,798.
Trail is the smallest city in Polk County, with a population of 38.
There are 14 cities in Polk County, Minnesota.