32 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| German Flatts | 1 | 12,051 | 12,230 | -0.11% | 358 | 34 | Town |
| Herkimer | 2 | 9,518 | 9,550 | 0.05% | 301 | 32 | Town |
| Ilion | 3 | 7,506 | 7,664 | -0.35% | 3,011 | 2 | Village |
| Herkimer | 4 | 7,237 | 7,287 | -0.11% | 2,796 | 3 | Village |
| Frankfort | 5 | 6,873 | 6,990 | -0.12% | 189 | 36 | Town |
| Little Falls | 6 | 4,499 | 4,582 | -0.31% | 1,172 | 4 | City |
| Mohawk | 7 | 3,540 | 3,564 | 0% | 102 | 35 | Town |
| Schuyler | 8 | 3,250 | 3,302 | -0.15% | 82 | 40 | Town |
| Manheim | 9 | 3,050 | 3,082 | -0.03% | 105 | 29 | Town |
| Mohawk | 10 | 2,358 | 2,412 | -0.38% | 2,689 | 1 | Village |
| Russia | 11 | 2,290 | 2,262 | 0.35% | 40 | 57 | Town |
| Frankfort | 12 | 2,277 | 2,321 | -0.31% | 2,246 | 1 | Village |
| Poland | 13 | 2,160 | 2,209 | -0.18% | 59 | 37 | Town |
| Newport | 14 | 2,103 | 2,137 | -0.1% | 66 | 32 | Town |
| Dolgeville | 15 | 2,000 | 2,044 | -0.35% | 1,117 | 2 | Village |
| Winfield | 16 | 1,879 | 1,896 | -0.11% | 79 | 24 | Town |
| Salisbury | 17 | 1,846 | 1,830 | 0.27% | 17 | 107 | Town |
| Webb | 18 | 1,842 | 1,794 | 0.66% | 4 | 451 | Town |
| Columbia | 19 | 1,605 | 1,568 | 0.44% | 46 | 35 | Town |
| Little Falls | 20 | 1,471 | 1,497 | -0.14% | 66 | 22 | Town |
| Fairfield | 21 | 1,450 | 1,472 | -0.07% | 35 | 41 | Town |
| Litchfield | 22 | 1,434 | 1,442 | -0.07% | 48 | 30 | Town |
| Warren | 23 | 1,012 | 1,029 | -0.1% | 27 | 38 | Town |
| Ohio | 24 | 985 | 964 | 0.51% | 3 | 301 | Town |
| Danube | 25 | 946 | 945 | -0.32% | 32 | 29 | Town |
| Norway | 26 | 769 | 744 | 1.05% | 22 | 36 | Town |
| West Winfield | 27 | 723 | 741 | -0.41% | 794 | 1 | Village |
| Stark | 28 | 706 | 715 | 0% | 22 | 32 | Town |
| Newport | 29 | 552 | 563 | -0.36% | 1,049 | 1 | Village |
| Poland | 30 | 475 | 484 | -0.21% | 875 | 1 | Village |
| Middleville | 31 | 428 | 436 | -0.23% | 559 | 1 | Village |
| Cold Brook | 32 | 258 | 267 | -0.39% | 588 | 0 | Village |
German Flatts is the largest city in Herkimer County, with a population of 12,051.
Cold Brook is the smallest city in Herkimer County, with a population of 258.
There are 32 cities in Herkimer County, New York.