48 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Lowville | 1 | 4,875 | 4,876 | -0.06% | 129 | 38 | Town |
| Lowville | 2 | 4,875 | 4,873 | -0.06% | 129 | 38 | Town |
| Lowville | 3 | 3,335 | 3,341 | -0.03% | 1,758 | 2 | Village |
| Lowville | 4 | 3,335 | 3,338 | -0.03% | 1,758 | 2 | Village |
| Croghan | 5 | 3,209 | 3,195 | 0.09% | 18 | 179 | Town |
| Croghan | 6 | 3,209 | 3,191 | 0.09% | 18 | 179 | Town |
| New Bremen | 7 | 2,779 | 2,786 | -0.07% | 50 | 56 | Town |
| New Bremen | 8 | 2,779 | 2,784 | -0.07% | 50 | 56 | Town |
| Denmark | 9 | 2,632 | 2,640 | -0.08% | 52 | 51 | Town |
| Denmark | 10 | 2,632 | 2,638 | -0.08% | 52 | 51 | Town |
| Watson | 11 | 1,790 | 1,796 | 0% | 16 | 114 | Town |
| Watson | 12 | 1,790 | 1,793 | 0% | 16 | 114 | Town |
| West Turin | 13 | 1,689 | 1,690 | 0.06% | 16 | 103 | Town |
| West Turin | 14 | 1,689 | 1,688 | 0.06% | 16 | 103 | Town |
| Diana | 15 | 1,608 | 1,612 | -0.12% | 12 | 138 | Town |
| Diana | 16 | 1,608 | 1,611 | -0.12% | 12 | 138 | Town |
| Leyden | 17 | 1,581 | 1,573 | -0.06% | 47 | 33 | Town |
| Leyden | 18 | 1,581 | 1,570 | -0.06% | 47 | 33 | Town |
| Martinsburg | 19 | 1,320 | 1,321 | 0% | 18 | 75 | Town |
| Martinsburg | 20 | 1,320 | 1,319 | 0% | 18 | 75 | Town |
| Greig | 21 | 1,189 | 1,184 | -0.17% | 13 | 93 | Town |
| Greig | 22 | 1,189 | 1,185 | -0.17% | 13 | 93 | Town |
| Lyonsdale | 23 | 1,155 | 1,172 | -0.35% | 17 | 68 | Town |
| Lyonsdale | 24 | 1,155 | 1,172 | -0.35% | 17 | 68 | Town |
| Turin | 25 | 764 | 765 | 0% | 24 | 31 | Town |
| Turin | 26 | 764 | 764 | 0% | 24 | 31 | Town |
| Copenhagen | 27 | 659 | 663 | -0.15% | 558 | 1 | Village |
| Copenhagen | 28 | 659 | 662 | -0.15% | 558 | 1 | Village |
| Croghan | 29 | 640 | 640 | 0% | 1,499 | 0 | Village |
| Croghan | 30 | 640 | 639 | 0% | 1,499 | 0 | Village |
| Lyons Falls | 31 | 596 | 596 | 0% | 615 | 1 | Village |
| Lyons Falls | 32 | 596 | 595 | 0% | 615 | 1 | Village |
| Port Leyden | 33 | 591 | 592 | 0% | 887 | 1 | Village |
| Port Leyden | 34 | 591 | 591 | 0% | 887 | 1 | Village |
| Harrisburg | 35 | 481 | 479 | 0% | 12 | 40 | Town |
| Harrisburg | 36 | 481 | 478 | 0% | 12 | 40 | Town |
| Castorland | 37 | 340 | 339 | 0% | 1,009 | 0 | Village |
| Castorland | 38 | 340 | 338 | 0% | 1,009 | 0 | Village |
| Pinckney | 39 | 312 | 313 | -0.32% | 8 | 41 | Town |
| Pinckney | 40 | 312 | 312 | -0.32% | 8 | 41 | Town |
| Constableville | 41 | 302 | 303 | 0% | 267 | 1 | Village |
| Constableville | 42 | 302 | 302 | 0% | 267 | 1 | Village |
| Osceola | 43 | 242 | 243 | 0% | 3 | 88 | Town |
| Osceola | 44 | 242 | 243 | 0% | 3 | 88 | Town |
| Turin | 45 | 214 | 214 | 0% | 207 | 1 | Village |
| Turin | 46 | 214 | 214 | 0% | 207 | 1 | Village |
| Montague | 47 | 96 | 96 | 0% | 2 | 64 | Town |
| Montague | 48 | 96 | 96 | 0% | 2 | 64 | Town |
Lowville is the largest city in Lewis County, with a population of 4,875.
Montague is the smallest city in Lewis County, with a population of 96.
There are 48 cities in Lewis County, New York.