16 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| International Falls | 1 | 5,427 | 5,798 | -1.29% | 798 | 7 | City |
| International Falls | 2 | 5,427 | 5,780 | -1.29% | 798 | 7 | City |
| Birchdale | 3 | 968 | 920 | 1.04% | 30 | 33 | Township |
| Birchdale | 4 | 968 | 922 | 1.04% | 30 | 33 | Township |
| Ranier | 5 | 533 | 568 | -1.3% | 498 | 1 | City |
| Ranier | 6 | 533 | 566 | -1.3% | 498 | 1 | City |
| Littlefork | 7 | 520 | 554 | -1.33% | 437 | 1 | City |
| Littlefork | 8 | 520 | 553 | -1.33% | 437 | 1 | City |
| Big Falls | 9 | 169 | 178 | -1.17% | 28 | 6 | City |
| Big Falls | 10 | 169 | 177 | -1.17% | 28 | 6 | City |
| Northome | 11 | 153 | 158 | -0.65% | 105 | 1 | City |
| Northome | 12 | 153 | 158 | -0.65% | 105 | 1 | City |
| Kabetogama | 13 | 140 | 139 | 0.72% | 8 | 17 | Township |
| Kabetogama | 14 | 140 | 139 | 0.72% | 8 | 17 | Township |
| Mizpah | 15 | 52 | 54 | -1.89% | 17 | 3 | City |
| Mizpah | 16 | 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 16 cities in Koochiching County, Minnesota.