| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Fergus Falls | 1 | 14,285 | 14,104 | 0.27% | 993 | 14 | City |
| Perham | 2 | 3,794 | 3,524 | 1.28% | 1,061 | 4 | City |
| Pelican Rapids | 3 | 2,608 | 2,596 | 0% | 1,010 | 3 | City |
| New York Mills | 4 | 1,512 | 1,352 | 2.09% | 1,019 | 1 | City |
| Parkers Prairie | 5 | 1,033 | 1,020 | 0.19% | 830 | 1 | City |
| Battle Lake | 6 | 943 | 858 | 1.4% | 656 | 1 | City |
| Henning | 7 | 859 | 857 | 0% | 260 | 3 | City |
| Ottertail | 8 | 754 | 641 | 2.72% | 176 | 4 | City |
| Vergas | 9 | 373 | 343 | 0.81% | 238 | 2 | City |
| Underwood | 10 | 363 | 357 | 0.28% | 618 | 1 | City |
| Deer Creek | 11 | 329 | 329 | 0% | 82 | 4 | City |
| Dalton | 12 | 213 | 216 | -0.47% | 899 | 0 | City |
| Bluffton | 13 | 212 | 212 | 0% | 78 | 3 | City |
| Dent | 14 | 170 | 170 | 0% | 470 | 0 | City |
| Elizabeth | 15 | 164 | 164 | 0% | 440 | 0 | City |
| Erhard | 16 | 132 | 132 | 0% | 239 | 1 | City |
| Richville | 17 | 82 | 80 | 0% | 83 | 1 | City |
| Clitherall | 18 | 72 | 63 | 1.41% | 377 | 0 | City |
| Vining | 19 | 54 | 56 | 0% | 47 | 1 | City |
| Doran | 20 | 30 | 32 | -3.23% | 145 | 0 | City |
Fergus Falls is the largest city in Otter Tail County, with a population of 14,285.
Doran is the smallest city in Otter Tail County, with a population of 30.
There are 20 cities in Otter Tail County, Minnesota.