27 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Duluth | 1 | 88,619 | 86,719 | 0.36% | 1,237 | 72 | City |
| Hibbing | 2 | 15,821 | 16,177 | -0.37% | 87 | 182 | City |
| Hermantown | 3 | 10,285 | 10,224 | 0.1% | 299 | 34 | City |
| Virginia | 4 | 8,194 | 8,412 | -0.44% | 437 | 19 | City |
| Chisholm | 5 | 4,619 | 4,763 | -0.52% | 1,034 | 4 | City |
| Rice Lake | 6 | 4,201 | 4,102 | 0.41% | 128 | 33 | City |
| Eveleth | 7 | 3,380 | 3,485 | -0.5% | 536 | 6 | City |
| Ely | 8 | 3,190 | 3,262 | -0.37% | 1,091 | 3 | City |
| Proctor | 9 | 3,057 | 3,114 | -0.29% | 910 | 3 | City |
| Mountain Iron | 10 | 2,836 | 2,868 | -0.18% | 42 | 68 | City |
| Hoyt Lakes | 11 | 1,974 | 2,016 | -0.35% | 35 | 56 | City |
| Aurora | 12 | 1,640 | 1,676 | -0.36% | 444 | 4 | City |
| Gilbert | 13 | 1,638 | 1,688 | -0.49% | 140 | 12 | City |
| Babbitt | 14 | 1,357 | 1,395 | -0.44% | 13 | 106 | City |
| Biwabik | 15 | 970 | 954 | 0.31% | 111 | 9 | City |
| Buhl | 16 | 941 | 952 | -0.21% | 285 | 3 | City |
| Cook | 17 | 517 | 526 | -0.19% | 199 | 3 | City |
| Floodwood | 18 | 515 | 520 | -0.19% | 269 | 2 | City |
| Tower | 19 | 417 | 428 | -0.48% | 143 | 3 | City |
| Orr | 20 | 211 | 217 | -0.47% | 150 | 1 | City |
| Winton | 21 | 162 | 165 | 0% | 1,328 | 0 | City |
| Kinney | 22 | 146 | 149 | 0% | 37 | 4 | City |
| Meadowlands | 23 | 142 | 135 | 0.71% | 368 | 0 | City |
| Brookston | 24 | 116 | 116 | 0% | 212 | 1 | City |
| Iron Junction | 25 | 105 | 108 | 0% | 129 | 1 | City |
| McKinley | 26 | 101 | 104 | 0% | 71 | 1 | City |
| Leonidas | 27 | 50 | 52 | 0% | 38 | 1 | City |
Duluth is the largest city in St. Louis County, with a population of 88,619.
Leonidas is the smallest city in St. Louis County, with a population of 50.
There are 27 cities in St. Louis County, Minnesota.