33 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Marshall | 1 | 13,942 | 13,852 | 0.13% | 1,348 | 10 | City |
| Tracy | 2 | 2,026 | 2,060 | -0.34% | 846 | 2 | City |
| Minneota | 3 | 1,340 | 1,360 | -0.3% | 924 | 1 | City |
| Cottonwood | 4 | 1,134 | 1,144 | -0.18% | 1,139 | 1 | City |
| Cottonwood | 5 | 835 | 852 | -0.6% | 24 | 35 | Township |
| Balaton | 6 | 579 | 589 | -0.34% | 399 | 1 | City |
| Lake Marshall | 7 | 549 | 554 | -0.36% | 19 | 28 | Township |
| Lynd | 8 | 425 | 434 | -0.47% | 367 | 1 | City |
| Lynd | 9 | 410 | 408 | 0.24% | 12 | 35 | Township |
| Ghent | 10 | 379 | 374 | 0.26% | 1,211 | 0 | City |
| Fairview | 11 | 364 | 370 | -0.55% | 11 | 33 | Township |
| Russell | 12 | 355 | 344 | 0.57% | 387 | 1 | City |
| Marshall | 13 | 305 | 314 | -0.97% | 9 | 35 | Township |
| Rock Lake | 14 | 273 | 275 | -0.36% | 8 | 33 | Township |
| Clifton | 15 | 260 | 263 | -0.38% | 7 | 36 | Township |
| Grandview | 16 | 257 | 260 | -0.39% | 7 | 35 | Township |
| Sodus | 17 | 257 | 259 | -0.39% | 7 | 36 | Township |
| Coon Creek | 18 | 249 | 249 | 0% | 7 | 36 | Township |
| Westerheim | 19 | 225 | 225 | 0% | 6 | 36 | Township |
| Minneota | 20 | 224 | 222 | 0.45% | 7 | 34 | Township |
| Vallers | 21 | 211 | 213 | -0.47% | 6 | 36 | Township |
| Eidsvold | 22 | 208 | 204 | 0.97% | 6 | 34 | Township |
| Lucas | 23 | 203 | 205 | -0.49% | 6 | 34 | Township |
| Stanley | 24 | 201 | 203 | -0.5% | 6 | 35 | Township |
| Amiret | 25 | 198 | 200 | -0.5% | 5 | 36 | Township |
| Nordland | 26 | 190 | 188 | 0.53% | 5 | 35 | Township |
| Lyons | 27 | 189 | 191 | -0.53% | 5 | 35 | Township |
| Shelburne | 28 | 185 | 189 | -0.54% | 5 | 35 | Township |
| Monroe | 29 | 181 | 183 | -0.55% | 5 | 34 | Township |
| Custer | 30 | 174 | 176 | -0.57% | 5 | 36 | Township |
| Island Lake | 31 | 173 | 171 | 0.58% | 5 | 36 | Township |
| Taunton | 32 | 130 | 135 | -0.76% | 129 | 1 | City |
| Garvin | 33 | 118 | 120 | 0% | 421 | 0 | City |
Marshall is the largest city in Lyon County, with a population of 13,942.
Garvin is the smallest city in Lyon County, with a population of 118.
There are 33 cities in Lyon County, Minnesota.