31 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Plattsburgh | 1 | 19,737 | 19,839 | -0.11% | 3,676 | 5 | City |
| Plattsburgh | 2 | 11,620 | 11,863 | -0.73% | 255 | 46 | Town |
| Peru | 3 | 6,637 | 6,773 | -0.23% | 84 | 79 | Town |
| Champlain | 4 | 5,570 | 5,738 | -0.62% | 109 | 51 | Town |
| Beekmantown | 5 | 5,341 | 5,500 | -0.61% | 88 | 60 | Town |
| Schuyler Falls | 6 | 5,071 | 4,841 | 2.61% | 137 | 37 | Town |
| Chazy | 7 | 4,007 | 4,091 | -0.3% | 74 | 54 | Town |
| Saranac | 8 | 3,791 | 3,849 | -0.11% | 33 | 115 | Town |
| Mooers | 9 | 3,443 | 3,458 | 0.47% | 39 | 87 | Town |
| Keeseville | 10 | 3,181 | 2,557 | 7.14% | 528 | 6 | CDP |
| Dannemora | 11 | 3,160 | 4,033 | 1.44% | 53 | 59 | Town |
| Au Sable | 12 | 3,113 | 3,181 | -0.42% | 80 | 39 | Town |
| Altona | 13 | 2,519 | 2,625 | -0.08% | 25 | 101 | Town |
| Rouses Point | 14 | 2,177 | 2,249 | -0.68% | 1,244 | 2 | Village |
| Dannemora | 15 | 2,158 | 3,286 | -9.48% | 1,788 | 1 | Village |
| Peru | 16 | 1,861 | 1,557 | 0.98% | 967 | 2 | CDP |
| Ellenburg | 17 | 1,775 | 1,835 | -0.45% | 17 | 107 | Town |
| Morrisonville | 18 | 1,662 | 1,551 | 0.42% | 494 | 3 | CDP |
| Black Brook | 19 | 1,415 | 1,440 | -0.35% | 11 | 130 | Town |
| Plattsburgh West | 20 | 1,293 | 1,230 | -0.39% | 682 | 2 | CDP |
| Cumberland Head | 21 | 1,290 | 1,495 | -1.68% | 334 | 4 | CDP |
| Champlain | 22 | 1,123 | 1,167 | -0.8% | 771 | 1 | Village |
| Cadyville | 23 | 686 | 525 | 7.19% | 632 | 1 | CDP |
| Altona | 24 | 639 | 819 | -0.93% | 374 | 2 | CDP |
| Au Sable Forks | 25 | 598 | 416 | 0.5% | 241 | 2 | CDP |
| Mooers | 26 | 545 | 442 | 1.3% | 449 | 1 | CDP |
| West Chazy | 27 | 469 | 400 | -0.85% | 250 | 2 | CDP |
| Chazy | 28 | 454 | 717 | -1.52% | 268 | 2 | CDP |
| Lyon Mountain | 29 | 207 | 287 | -6.33% | 20 | 11 | CDP |
| Redford | 30 | 201 | 258 | -8.22% | 149 | 1 | CDP |
| Parc | 31 | 150 | 225 | -4.46% | 122 | 1 | CDP |
Plattsburgh is the largest city in Clinton County, with a population of 19,737.
Parc is the smallest city in Clinton County, with a population of 150.
There are 31 cities in Clinton County, New York.