8 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| International Falls | 1 | 5,427 | 5,780 | -1.29% | 798 | 7 | City |
| Birchdale | 2 | 968 | 922 | 1.04% | 30 | 33 | Township |
| Ranier | 3 | 533 | 566 | -1.3% | 498 | 1 | City |
| Littlefork | 4 | 520 | 553 | -1.33% | 437 | 1 | City |
| Big Falls | 5 | 169 | 177 | -1.17% | 28 | 6 | City |
| Northome | 6 | 153 | 158 | -0.65% | 105 | 1 | City |
| Kabetogama | 7 | 140 | 139 | 0.72% | 8 | 17 | Township |
| Mizpah | 8 | 52 | 54 | -1.89% | 17 | 3 | City |
International Falls is the largest city in Koochiching County, with a population of 5,427.
Mizpah is the smallest city in Koochiching County, with a population of 52.
There are 8 cities in Koochiching County, Minnesota.