17 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Schenectady | 1 | 69,782 | 67,039 | 0.41% | 6,457 | 11 | City |
| Schenectady | 2 | 69,782 | 68,347 | 0.41% | 6,457 | 11 | City |
| Rotterdam | 3 | 31,359 | 30,521 | 1.22% | 879 | 36 | Town |
| Rotterdam | 4 | 31,359 | 30,528 | 1.22% | 879 | 36 | Town |
| Glenville | 5 | 30,028 | 29,316 | 1.19% | 609 | 49 | Town |
| Glenville | 6 | 30,028 | 29,276 | 1.19% | 609 | 49 | Town |
| Niskayuna | 7 | 24,352 | 23,276 | 1.31% | 1,721 | 14 | Town |
| Niskayuna | 8 | 24,352 | 23,253 | 1.31% | 1,721 | 14 | Town |
| East Glenville | 9 | 12,692 | 11,184 | 3.3% | 1,262 | 10 | CDP |
| Duanesburg | 10 | 6,073 | 5,872 | 1.52% | 86 | 71 | Town |
| Duanesburg | 11 | 6,073 | 5,869 | 1.52% | 86 | 71 | Town |
| Princetown | 12 | 2,124 | 2,021 | 1.63% | 89 | 24 | Town |
| Princetown | 13 | 2,124 | 2,021 | 1.63% | 89 | 24 | Town |
| Duanesburg | 14 | 310 | 341 | -1.59% | 126 | 2 | CDP |
| Delanson | 15 | 309 | 308 | 0% | 480 | 1 | Village |
| Delanson | 16 | 309 | 308 | 0% | 480 | 1 | Village |
| Duane Lake | 17 | 190 | 216 | -4.52% | 79 | 2 | CDP |
Schenectady is the largest city in Schenectady County, with a population of 69,782.
Duane Lake is the smallest city in Schenectady County, with a population of 190.
There are 17 cities in Schenectady County, New York.