Note: As defined by the US Census Bureau, a city's official boundaries often extend miles beyond the city itself and may even cross county lines. As such, several thousand US cities officially exist in two or more counties (and therefore appear on multiple counties' lists of cities.)
City | Rank | 2024 Pop. | 2020 Pop. | Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Oswego | 1 | 17,057 | 16,915 | 0.21% | 2,240 | 7.6 | City |
| Fulton | 2 | 11,207 | 11,371 | -0.36% | 2,857 | 3.9 | City |
| Hastings | 3 | 9,355 | 9,337 | 0.07% | 205 | 45.6 | Town |
| Oswego | 4 | 8,606 | 7,918 | -0.15% | 315 | 27.3 | Town |
| Schroeppel | 5 | 7,922 | 7,960 | -0.15% | 188 | 42.2 | Town |
| Scriba | 6 | 6,641 | 6,612 | 0.5% | 164 | 40.6 | Town |
| Granby | 7 | 6,483 | 6,520 | -0.09% | 146 | 44.5 | Town |
| Richland | 8 | 5,730 | 5,619 | 0.09% | 100 | 57.3 | Town |
| Volney | 9 | 5,644 | 5,659 | 0.02% | 117 | 48.2 | Town |
| Mexico | 10 | 5,310 | 5,260 | 0.32% | 115 | 46.3 | Town |
| Constantia | 11 | 4,763 | 4,777 | -0.02% | 84 | 56.8 | Town |
| Hannibal | 12 | 4,449 | 4,516 | -0.34% | 100 | 44.7 | Town |
| West Monroe | 13 | 4,036 | 4,086 | -0.35% | 120 | 33.7 | Town |
| Sandy Creek | 14 | 3,809 | 3,811 | -0.03% | 90 | 42.3 | Town |
| Palermo | 15 | 3,440 | 3,465 | -0.2% | 85 | 40.5 | Town |
| New Haven | 16 | 2,979 | 2,926 | 0.24% | 96 | 31.1 | Town |
| Parish | 17 | 2,375 | 2,392 | -0.17% | 57 | 41.7 | Town |
| Pulaski | 18 | 2,300 | 2,176 | 1.37% | 650 | 3.5 | Village |
| Phoenix | 19 | 2,194 | 2,222 | -0.32% | 1,874 | 1.2 | Village |
| Central Square | 20 | 1,833 | 1,860 | -0.38% | 962 | 1.9 | Village |
| Minetto | 21 | 1,613 | 1,636 | -0.31% | 280 | 5.8 | Town |
| Mexico | 22 | 1,551 | 1,574 | -0.39% | 723 | 2.1 | Village |
| Williamstown | 23 | 1,348 | 1,333 | 0.37% | 35 | 38.7 | Town |
| Amboy | 24 | 1,276 | 1,247 | 0.55% | 34 | 37.0 | Town |
| Fulton | 25 | 1,215 | 1,202 | 0.33% | 19 | 65.0 | Town |
| Orwell | 26 | 1,078 | 1,074 | 0.19% | 27 | 39.6 | Town |
| Cleveland | 27 | 729 | 736 | -0.27% | 645 | 1.1 | Village |
| Lacona | 28 | 666 | 674 | -0.3% | 599 | 1.1 | Village |
| Sandy Creek | 29 | 619 | 625 | -0.32% | 459 | 1.3 | Village |
| Hannibal | 30 | 536 | 543 | -0.37% | 465 | 1.2 | Village |
| Parish | 31 | 443 | 451 | -0.45% | 281 | 1.6 | Village |
Note: City markers shown outside the county boundary mean that a part of the city extends into this county, but is primarily located in an adjacent county.
Oswego is the largest city in Oswego County.
Parish is the smallest city in Oswego County.
There are 31 cities in Oswego County, New York.