8 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| International Falls | 1 | 5,478 | 5,790 | -1.12% | 806 | 6.80 | City |
| Birchdale township | 2 | 968 | 927 | 0.94% | 30 | 32.72 | Township |
| Ranier | 3 | 533 | 563 | -1.11% | 498 | 1.07 | City |
| Littlefork | 4 | 525 | 552 | -0.94% | 441 | 1.19 | City |
| Big Falls | 5 | 171 | 175 | -0.58% | 28 | 6.04 | City |
| Northome | 6 | 152 | 156 | -0.65% | 104 | 1.46 | City |
| Kabetogama township | 7 | 137 | 138 | 0% | 8 | 17.45 | Township |
| Mizpah | 8 | 51 | 51 | 0% | 17 | 3.02 | City |
International Falls is the largest city in Koochiching County, with a population of 5,478.
Mizpah is the smallest city in Koochiching County.
There are 8 cities in Koochiching County, Minnesota.