27 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Fairmont | 1 | 10,109 | 10,444 | -0.66% | 674 | 15 | City |
| Truman | 2 | 1,062 | 1,097 | -0.65% | 966 | 1 | City |
| Sherburn | 3 | 1,047 | 1,061 | -0.29% | 1,139 | 1 | City |
| Welcome | 4 | 691 | 709 | -0.58% | 475 | 1 | City |
| Trimont | 5 | 683 | 710 | -0.87% | 869 | 1 | City |
| Rutland | 6 | 364 | 369 | -0.27% | 10 | 36 | Township |
| Fairmont | 7 | 306 | 312 | -0.65% | 15 | 21 | Township |
| Manyaska | 8 | 303 | 309 | -0.98% | 9 | 34 | Township |
| Ceylon | 9 | 292 | 305 | -1.02% | 565 | 1 | City |
| Granada | 10 | 279 | 289 | -0.71% | 489 | 1 | City |
| East Chain | 11 | 271 | 278 | -1.09% | 8 | 35 | Township |
| Fraser | 12 | 268 | 273 | -0.74% | 7 | 36 | Township |
| Fox Lake | 13 | 257 | 258 | 0% | 8 | 34 | Township |
| Westford | 14 | 245 | 250 | -0.81% | 7 | 36 | Township |
| Rolling Green | 15 | 243 | 248 | -0.82% | 7 | 34 | Township |
| Jay | 16 | 230 | 234 | -0.43% | 6 | 36 | Township |
| Pleasant Prairie | 17 | 226 | 232 | -0.88% | 6 | 36 | Township |
| Tenhassen | 18 | 225 | 231 | -0.88% | 7 | 33 | Township |
| Northrop | 19 | 215 | 224 | -0.92% | 1,641 | 0 | City |
| Center Creek | 20 | 211 | 216 | -0.94% | 6 | 35 | Township |
| Galena | 21 | 203 | 208 | -0.98% | 6 | 35 | Township |
| Nashville | 22 | 201 | 206 | -0.99% | 6 | 36 | Township |
| Lake Belt | 23 | 181 | 186 | -1.09% | 5 | 35 | Township |
| Elm Creek | 24 | 159 | 162 | -0.63% | 5 | 35 | Township |
| Lake Fremont | 25 | 150 | 154 | -1.32% | 4 | 36 | Township |
| Dunnell | 26 | 125 | 132 | -1.57% | 817 | 0 | City |
| Ormsby | 27 | 123 | 121 | 0% | 348 | 0 | City |
Fairmont is the largest city in Martin County, with a population of 10,109.
Ormsby is the smallest city in Martin County, with a population of 123.
There are 27 cities in Martin County, Minnesota.