| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Thief River Falls | 1 | 8,799 | 8,836 | 0% | 1,466 | 6 | City |
| St. Hilaire | 2 | 255 | 273 | -1.54% | 326 | 1 | City |
| Goodridge | 3 | 107 | 111 | -0.93% | 569 | 0 | City |
Thief River Falls is the largest city in Pennington County, with a population of 8,799.
Goodridge is the smallest city in Pennington County, with a population of 107.
There are 3 cities in Pennington County, Minnesota.