9 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Sabetha | 1 | 2,445 | 2,538 | -0.61% | 734 | 3 | City |
| Seneca | 2 | 2,140 | 2,142 | 0% | 1,197 | 2 | City |
| Centralia | 3 | 495 | 482 | 0.41% | 1,090 | 0 | City |
| Wetmore | 4 | 334 | 348 | -0.6% | 863 | 0 | City |
| Corning | 5 | 206 | 214 | -0.48% | 678 | 0 | City |
| Bern | 6 | 160 | 166 | -0.62% | 563 | 0 | City |
| Wheaton | 7 | 110 | 98 | 1.85% | 714 | 0 | City |
| Goff | 8 | 102 | 104 | 0% | 495 | 0 | City |
| Oneida | 9 | 57 | 60 | 0% | 248 | 0 | City |
Sabetha is the largest city in Nemaha County, with a population of 2,445.
Oneida is the smallest city in Nemaha County, with a population of 57.
There are 9 cities in Nemaha County, Kansas.