| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Syracuse | 1 | 144,220 | 148,106 | -0.47% | 5,755 | 25 | City |
| Clay | 2 | 59,078 | 60,361 | -0.35% | 1,229 | 48 | Town |
| Manlius | 3 | 32,705 | 33,656 | -0.48% | 665 | 49 | Town |
| Salina | 4 | 32,183 | 33,220 | -0.59% | 2,359 | 14 | Town |
| Cicero | 5 | 30,697 | 31,472 | -0.38% | 634 | 48 | Town |
| De Witt | 6 | 25,468 | 25,966 | -0.07% | 756 | 34 | Town |
| Camillus | 7 | 25,000 | 25,361 | -0.35% | 728 | 34 | Town |
| Lysander | 8 | 23,129 | 23,068 | 0.08% | 375 | 62 | Town |
| Onondaga | 9 | 22,374 | 22,809 | -0.25% | 388 | 58 | Town |
| Geddes | 10 | 16,492 | 17,007 | -0.52% | 1,798 | 9 | Town |
| Van Buren | 11 | 13,954 | 14,325 | -0.6% | 394 | 35 | Town |
| Baldwinsville | 12 | 7,538 | 7,803 | -0.58% | 2,363 | 3 | Village |
| Skaneateles | 13 | 6,988 | 7,105 | -0.4% | 164 | 43 | Town |
| Pompey | 14 | 6,971 | 7,070 | -0.34% | 105 | 66 | Town |
| North Syracuse | 15 | 6,775 | 6,711 | 0.03% | 3,410 | 2 | Village |
| Solvay | 16 | 6,385 | 6,629 | -0.65% | 3,951 | 2 | Village |
| Marcellus | 17 | 5,943 | 6,060 | -0.27% | 183 | 32 | Town |
| Elbridge | 18 | 5,391 | 5,478 | -0.22% | 144 | 38 | Town |
| LaFayette | 19 | 4,894 | 4,909 | 0.31% | 125 | 39 | Town |
| Manlius | 20 | 4,556 | 4,703 | -0.59% | 2,502 | 2 | Village |
| Fayetteville | 21 | 4,102 | 4,249 | -0.58% | 2,364 | 2 | Village |
| Minoa | 22 | 3,613 | 3,685 | -0.3% | 2,735 | 1 | Village |
| East Syracuse | 23 | 2,952 | 3,073 | -0.71% | 1,892 | 2 | Village |
| Tully | 24 | 2,605 | 2,669 | -0.5% | 101 | 26 | Town |
| Skaneateles | 25 | 2,496 | 2,543 | -0.28% | 1,754 | 1 | Village |
| Otisco | 26 | 2,366 | 2,369 | -0.08% | 80 | 29 | Town |
| Liverpool | 27 | 2,218 | 2,297 | -0.58% | 2,953 | 1 | Village |
| Fabius | 28 | 1,955 | 1,998 | -0.31% | 42 | 47 | Town |
| Marcellus | 29 | 1,754 | 1,794 | -0.4% | 2,745 | 1 | Village |
| Spafford | 30 | 1,595 | 1,587 | -0.06% | 49 | 33 | Town |
| Camillus | 31 | 1,268 | 1,224 | 0.79% | 3,123 | 0 | Village |
| Jordan | 32 | 1,187 | 1,225 | -0.59% | 1,020 | 1 | Village |
| Elbridge | 33 | 945 | 973 | -0.53% | 951 | 1 | Village |
| Tully | 34 | 885 | 911 | -0.56% | 1,211 | 1 | Village |
| Fabius | 35 | 319 | 332 | -0.62% | 749 | 0 | Village |
Syracuse is the largest city in Onondaga County, with a population of 144,220.
Fabius is the smallest city in Onondaga County, with a population of 319.
There are 35 cities in Onondaga County, New York.