35 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Syracuse | 1 | 144,782 | 146,726 | -0.27% | 5,778 | 25.06 | City |
| Clay | 2 | 59,122 | 60,437 | -0.39% | 1,230 | 48.06 | Town |
| Manlius | 3 | 32,717 | 33,662 | -0.48% | 666 | 49.15 | Town |
| Salina | 4 | 32,119 | 33,212 | -0.56% | 2,354 | 13.64 | Town |
| Cicero | 5 | 30,653 | 31,397 | -0.39% | 633 | 48.42 | Town |
| Camillus | 6 | 25,127 | 25,364 | -0.07% | 731 | 34.36 | Town |
| De Witt | 7 | 24,934 | 26,101 | -0.75% | 740 | 33.70 | Town |
| Lysander | 8 | 22,925 | 23,068 | -0.11% | 371 | 61.71 | Town |
| Onondaga | 9 | 22,250 | 22,816 | -0.26% | 386 | 57.63 | Town |
| Geddes | 10 | 16,562 | 17,002 | -0.4% | 1,806 | 9.17 | Town |
| Van Buren | 11 | 14,046 | 14,331 | -0.34% | 396 | 35.46 | Town |
| Baldwinsville | 12 | 7,527 | 7,806 | -0.74% | 2,360 | 3.19 | Village |
| Skaneateles | 13 | 7,024 | 7,113 | -0.24% | 165 | 42.61 | Town |
| Pompey | 14 | 6,983 | 7,069 | -0.26% | 105 | 66.42 | Town |
| North Syracuse | 15 | 6,784 | 6,731 | 0.16% | 3,414 | 1.99 | Village |
| Solvay | 16 | 6,385 | 6,632 | -0.76% | 3,951 | 1.62 | Village |
| Marcellus | 17 | 5,909 | 6,060 | -0.46% | 182 | 32.47 | Town |
| Elbridge | 18 | 5,360 | 5,469 | -0.32% | 143 | 37.56 | Town |
| LaFayette | 19 | 4,823 | 4,903 | -0.27% | 123 | 39.27 | Town |
| Manlius | 20 | 4,526 | 4,693 | -0.72% | 2,485 | 1.82 | Village |
| Fayetteville | 21 | 4,109 | 4,261 | -0.73% | 2,368 | 1.74 | Village |
| Minoa | 22 | 3,606 | 3,685 | -0.44% | 2,730 | 1.32 | Village |
| East Syracuse | 23 | 2,956 | 3,071 | -0.77% | 1,895 | 1.56 | Village |
| Tully | 24 | 2,616 | 2,670 | -0.19% | 101 | 25.87 | Town |
| Skaneateles | 25 | 2,503 | 2,545 | -0.32% | 1,759 | 1.42 | Village |
| Otisco | 26 | 2,371 | 2,369 | 0.17% | 80 | 29.46 | Town |
| Liverpool | 27 | 2,218 | 2,297 | -0.72% | 2,953 | 0.75 | Village |
| Fabius | 28 | 1,960 | 2,003 | -0.3% | 42 | 46.50 | Town |
| Marcellus | 29 | 1,730 | 1,792 | -0.69% | 2,707 | 0.64 | Village |
| Spafford | 30 | 1,615 | 1,587 | 0.75% | 50 | 32.61 | Town |
| Camillus | 31 | 1,303 | 1,223 | 1.24% | 3,209 | 0.41 | Village |
| Jordan | 32 | 1,188 | 1,225 | -0.59% | 1,021 | 1.16 | Village |
| Elbridge | 33 | 937 | 972 | -0.74% | 943 | 0.99 | Village |
| Tully | 34 | 877 | 911 | -0.79% | 1,200 | 0.73 | Village |
| Fabius | 35 | 321 | 333 | -0.62% | 754 | 0.43 | Village |
Syracuse is the largest city in Onondaga County, with a population of 144,782.
Fabius is the smallest city in Onondaga County.
There are 35 cities in Onondaga County, New York.