17 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Plattsburgh | 1 | 19,717 | 19,839 | -0.1% | 3,672 | 5 | City |
| Plattsburgh | 2 | 11,534 | 11,863 | -0.74% | 253 | 46 | Town |
| Peru | 3 | 6,622 | 6,773 | -0.23% | 84 | 79 | Town |
| Champlain | 4 | 5,535 | 5,738 | -0.63% | 108 | 51 | Town |
| Beekmantown | 5 | 5,308 | 5,500 | -0.62% | 88 | 60 | Town |
| Schuyler Falls | 6 | 5,200 | 4,841 | 2.54% | 141 | 37 | Town |
| Chazy | 7 | 3,995 | 4,091 | -0.3% | 74 | 54 | Town |
| Saranac | 8 | 3,787 | 3,849 | -0.11% | 33 | 115 | Town |
| Mooers | 9 | 3,459 | 3,458 | 0.46% | 40 | 87 | Town |
| Dannemora | 10 | 3,205 | 4,033 | 1.42% | 54 | 59 | Town |
| Au Sable | 11 | 3,100 | 3,181 | -0.42% | 80 | 39 | Town |
| Altona | 12 | 2,517 | 2,625 | -0.08% | 25 | 101 | Town |
| Rouses Point | 13 | 2,163 | 2,249 | -0.64% | 1,236 | 2 | Village |
| Dannemora | 14 | 1,933 | 3,286 | -10.43% | 1,601 | 1 | Village |
| Ellenburg | 15 | 1,767 | 1,835 | -0.45% | 17 | 107 | Town |
| Black Brook | 16 | 1,410 | 1,440 | -0.35% | 11 | 130 | Town |
| Champlain | 17 | 1,114 | 1,167 | -0.8% | 765 | 1 | Village |
Plattsburgh is the largest city in Clinton County, with a population of 19,717.
Champlain is the smallest city in Clinton County, with a population of 1,114.
There are 17 cities in Clinton County, New York.