27 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Fairmont | 1 | 10,042 | 10,444 | -0.66% | 670 | 15 | City |
| Truman | 2 | 1,055 | 1,097 | -0.66% | 960 | 1 | City |
| Sherburn | 3 | 1,044 | 1,061 | -0.29% | 1,136 | 1 | City |
| Welcome | 4 | 688 | 709 | -0.43% | 473 | 1 | City |
| Trimont | 5 | 678 | 710 | -0.73% | 863 | 1 | City |
| Rutland | 6 | 363 | 369 | -0.27% | 10 | 36 | Township |
| Fairmont | 7 | 304 | 312 | -0.65% | 15 | 21 | Township |
| Manyaska | 8 | 300 | 309 | -0.99% | 9 | 34 | Township |
| Ceylon | 9 | 290 | 305 | -0.68% | 561 | 1 | City |
| Granada | 10 | 277 | 289 | -0.72% | 485 | 1 | City |
| East Chain | 11 | 268 | 278 | -1.11% | 8 | 35 | Township |
| Fraser | 12 | 266 | 273 | -0.75% | 7 | 36 | Township |
| Fox Lake | 13 | 257 | 258 | 0% | 8 | 34 | Township |
| Westford | 14 | 243 | 250 | -0.82% | 7 | 36 | Township |
| Rolling Green | 15 | 241 | 248 | -0.82% | 7 | 34 | Township |
| Jay | 16 | 229 | 234 | -0.43% | 6 | 36 | Township |
| Pleasant Prairie | 17 | 224 | 232 | -0.88% | 6 | 36 | Township |
| Tenhassen | 18 | 223 | 231 | -0.89% | 7 | 33 | Township |
| Northrop | 19 | 213 | 224 | -0.93% | 1,626 | 0 | City |
| Center Creek | 20 | 209 | 216 | -0.95% | 6 | 35 | Township |
| Galena | 21 | 201 | 208 | -0.99% | 6 | 35 | Township |
| Nashville | 22 | 199 | 206 | -1% | 5 | 36 | Township |
| Lake Belt | 23 | 179 | 186 | -1.1% | 5 | 35 | Township |
| Elm Creek | 24 | 158 | 162 | -0.63% | 5 | 35 | Township |
| Lake Fremont | 25 | 148 | 154 | -1.33% | 4 | 36 | Township |
| Dunnell | 26 | 124 | 132 | -0.8% | 810 | 0 | City |
| Ormsby | 27 | 124 | 121 | 0.81% | 351 | 0 | City |
Fairmont is the largest city in Martin County, with a population of 10,042.
Ormsby is the smallest city in Martin County, with a population of 124.
There are 27 cities in Martin County, Minnesota.