35 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Syracuse | 1 | 145,887 | 146,934 | -0.14% | 5,822 | 25 | City |
| Clay | 2 | 59,801 | 60,437 | 0.06% | 1,244 | 48 | Town |
| Manlius | 3 | 33,186 | 33,663 | 0.1% | 675 | 49 | Town |
| Salina | 4 | 32,820 | 33,214 | 0.38% | 2,405 | 14 | Town |
| Cicero | 5 | 30,981 | 31,396 | 0.02% | 640 | 48 | Town |
| Camillus | 6 | 25,348 | 25,362 | 0.25% | 738 | 34 | Town |
| De Witt | 7 | 25,277 | 25,900 | -0.27% | 750 | 34 | Town |
| Lysander | 8 | 23,308 | 23,073 | 0.59% | 378 | 62 | Town |
| Onondaga | 9 | 22,621 | 22,817 | 0.44% | 392 | 58 | Town |
| Geddes | 10 | 16,751 | 17,006 | 0.03% | 1,827 | 9 | Town |
| Van Buren | 11 | 14,204 | 14,335 | 0.07% | 401 | 35 | Town |
| Baldwinsville | 12 | 7,624 | 7,811 | -0.5% | 2,390 | 3 | Village |
| Skaneateles | 13 | 7,110 | 7,113 | 0.25% | 167 | 43 | Town |
| Pompey | 14 | 7,060 | 7,074 | 0.17% | 106 | 66 | Town |
| North Syracuse | 15 | 6,771 | 6,720 | 0.15% | 3,408 | 2 | Village |
| Solvay | 16 | 6,460 | 6,632 | -0.54% | 3,998 | 2 | Village |
| Marcellus | 17 | 6,029 | 6,060 | 0.43% | 186 | 32 | Town |
| Elbridge | 18 | 5,434 | 5,471 | 0.2% | 145 | 38 | Town |
| LaFayette | 19 | 4,880 | 4,903 | 0.23% | 124 | 39 | Town |
| Manlius | 20 | 4,589 | 4,698 | -0.48% | 2,520 | 2 | Village |
| Fayetteville | 21 | 4,160 | 4,257 | -0.48% | 2,398 | 2 | Village |
| Minoa | 22 | 3,650 | 3,685 | -0.19% | 2,763 | 1 | Village |
| East Syracuse | 23 | 2,991 | 3,073 | -0.57% | 1,917 | 2 | Village |
| Tully | 24 | 2,653 | 2,674 | 0.26% | 103 | 26 | Town |
| Skaneateles | 25 | 2,526 | 2,546 | -0.16% | 1,775 | 1 | Village |
| Otisco | 26 | 2,390 | 2,366 | 0.59% | 81 | 29 | Town |
| Liverpool | 27 | 2,246 | 2,298 | -0.49% | 2,991 | 1 | Village |
| Fabius | 28 | 1,973 | 1,999 | -0.05% | 42 | 47 | Town |
| Marcellus | 29 | 1,769 | 1,793 | -0.28% | 2,768 | 1 | Village |
| Spafford | 30 | 1,614 | 1,589 | 0.56% | 49 | 33 | Town |
| Camillus | 31 | 1,286 | 1,225 | 0.94% | 3,167 | 0 | Village |
| Jordan | 32 | 1,203 | 1,228 | -0.41% | 1,034 | 1 | Village |
| Elbridge | 33 | 953 | 973 | -0.42% | 959 | 1 | Village |
| Tully | 34 | 894 | 914 | -0.45% | 1,223 | 1 | Village |
| Fabius | 35 | 322 | 332 | -0.62% | 756 | 0 | Village |
Syracuse is the largest city in Onondaga County, with a population of 145,887.
Fabius is the smallest city in Onondaga County, with a population of 322.
There are 35 cities in Onondaga County, New York.