20 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Minneapolis | 1 | 1,939 | 1,939 | 0% | 1,058 | 2 | City |
| Bennington | 2 | 1,304 | 1,238 | 0.85% | 31 | 42 | Township |
| Bennington | 3 | 656 | 619 | 1.08% | 1,562 | 0 | City |
| Sheridan | 4 | 414 | 410 | 0% | 11 | 36 | Township |
| Morton | 5 | 405 | 400 | 0% | 11 | 36 | Township |
| Delphos | 6 | 301 | 300 | 0% | 508 | 1 | City |
| Tescott | 7 | 266 | 266 | 0% | 689 | 0 | City |
| Concord | 8 | 259 | 248 | 0.78% | 7 | 35 | Township |
| Culver | 9 | 235 | 231 | 0% | 6 | 36 | Township |
| Richland | 10 | 222 | 214 | 0% | 6 | 36 | Township |
| Mentor | 11 | 164 | 74 | 7.19% | 424 | 0 | CDP |
| Fountain | 12 | 149 | 144 | 0% | 4 | 36 | Township |
| Buckeye | 13 | 118 | 116 | -0.84% | 4 | 30 | Township |
| Blaine | 14 | 106 | 103 | 0% | 3 | 36 | Township |
| Grant | 15 | 94 | 91 | 0% | 3 | 36 | Township |
| Center | 16 | 79 | 76 | 0% | 2 | 36 | Township |
| Stanton | 17 | 46 | 42 | 4.55% | 1 | 37 | Township |
| Sherman | 18 | 41 | 39 | 0% | 1 | 36 | Township |
| Henry | 19 | 28 | 28 | 0% | 1 | 36 | Township |
| Bavaria | 20 | 27 | 47 | 3.85% | 118 | 0 | CDP |
Minneapolis is the largest city in Ottawa County, with a population of 1,939.
Bavaria is the smallest city in Ottawa County, with a population of 27.
There are 20 cities in Ottawa County, Kansas.