28 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Duluth | 1 | 88,318 | 86,722 | 0.36% | 1,232 | 71.66 | City |
| Hibbing | 2 | 15,849 | 16,173 | -0.41% | 87 | 182.03 | City |
| Virginia | 3 | 8,214 | 8,406 | -0.46% | 438 | 18.77 | City |
| Chisholm | 4 | 4,637 | 4,761 | -0.54% | 1,038 | 4.47 | City |
| Rice Lake | 5 | 4,200 | 4,100 | 0.48% | 131 | 32.10 | City |
| Eveleth | 6 | 3,398 | 3,487 | -0.53% | 539 | 6.30 | City |
| Ely | 7 | 3,199 | 3,258 | -0.37% | 1,094 | 2.92 | City |
| Proctor | 8 | 3,068 | 3,115 | -0.29% | 913 | 3.36 | City |
| Mountain Iron | 9 | 2,844 | 2,868 | -0.18% | 42 | 68.11 | City |
| Hoyt Lakes | 10 | 1,972 | 2,016 | -0.45% | 35 | 55.91 | City |
| Gilbert | 11 | 1,648 | 1,688 | -0.48% | 141 | 11.68 | City |
| Aurora | 12 | 1,646 | 1,680 | -0.42% | 445 | 3.70 | City |
| Babbitt | 13 | 1,364 | 1,394 | -0.44% | 13 | 105.95 | City |
| Biwabik | 14 | 967 | 956 | 0.21% | 110 | 8.76 | City |
| Buhl | 15 | 943 | 952 | -0.21% | 285 | 3.31 | City |
| Cook | 16 | 522 | 527 | -0.19% | 201 | 2.60 | City |
| Floodwood | 17 | 516 | 521 | -0.19% | 298 | 1.73 | City |
| Tower | 18 | 421 | 428 | -0.24% | 144 | 2.92 | City |
| Soudan | 19 | 417 | 467 | -0.48% | 613 | 0.68 | CDP |
| Nett Lake | 20 | 254 | 249 | 7.17% | 148 | 1.72 | CDP |
| Orr | 21 | 209 | 216 | -0.48% | 149 | 1.40 | City |
| Winton | 22 | 165 | 165 | 0% | 1,352 | 0.12 | City |
| Kinney | 23 | 147 | 151 | -0.68% | 38 | 3.91 | City |
| Meadowlands | 24 | 136 | 133 | 0.74% | 352 | 0.39 | City |
| Brookston | 25 | 112 | 114 | 0% | 205 | 0.55 | City |
| Iron Junction | 26 | 106 | 108 | 0% | 131 | 0.81 | City |
| McKinley | 27 | 102 | 104 | 0% | 72 | 1.43 | City |
| Leonidas | 28 | 49 | 51 | 0% | 37 | 1.33 | City |
Duluth is the largest city in St. Louis County, with a population of 88,318.
Leonidas is the smallest city in St. Louis County.
There are 28 cities in St. Louis County, Minnesota.