20 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Fergus Falls | 1 | 14,329 | 14,116 | 0.25% | 996 | 14 | City |
| Perham | 2 | 3,804 | 3,515 | 1.28% | 1,063 | 4 | City |
| Pelican Rapids | 3 | 2,594 | 2,594 | 0% | 1,005 | 3 | City |
| New York Mills | 4 | 1,545 | 1,352 | 2.11% | 1,041 | 1 | City |
| Parkers Prairie | 5 | 1,035 | 1,017 | 0.29% | 831 | 1 | City |
| Battle Lake | 6 | 942 | 858 | 1.51% | 656 | 1 | City |
| Henning | 7 | 858 | 855 | 0.12% | 260 | 3 | City |
| Ottertail | 8 | 763 | 637 | 2.83% | 178 | 4 | City |
| Underwood | 9 | 366 | 357 | 0.55% | 624 | 1 | City |
| Vergas | 10 | 362 | 346 | 0.84% | 231 | 2 | City |
| Deer Creek | 11 | 332 | 332 | 0% | 83 | 4 | City |
| Dalton | 12 | 213 | 216 | 0% | 899 | 0 | City |
| Bluffton | 13 | 212 | 212 | 0% | 78 | 3 | City |
| Dent | 14 | 170 | 170 | 0% | 470 | 0 | City |
| Elizabeth | 15 | 165 | 165 | 0% | 442 | 0 | City |
| Erhard | 16 | 132 | 132 | 0% | 239 | 1 | City |
| Richville | 17 | 77 | 77 | 0% | 78 | 1 | City |
| Clitherall | 18 | 74 | 62 | 2.78% | 387 | 0 | City |
| Vining | 19 | 59 | 59 | 0% | 51 | 1 | City |
| Doran | 20 | 29 | 31 | 0% | 140 | 0 | City |
Fergus Falls is the largest city in Otter Tail County, with a population of 14,329.
Doran is the smallest city in Otter Tail County, with a population of 29.
There are 20 cities in Otter Tail County, Minnesota.