| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Cortland | 1 | 17,390 | 17,504 | -0.02% | 4,466 | 4 | City |
| Cortlandville | 2 | 8,165 | 8,413 | -0.32% | 164 | 50 | Town |
| Homer | 3 | 6,037 | 6,289 | -0.66% | 120 | 50 | Town |
| Homer | 4 | 3,027 | 3,186 | -0.88% | 1,572 | 2 | Village |
| Virgil | 5 | 2,362 | 2,425 | -0.55% | 50 | 47 | Town |
| Marathon | 6 | 1,947 | 2,034 | -0.66% | 78 | 25 | Town |
| Preble | 7 | 1,296 | 1,356 | -0.69% | 48 | 27 | Town |
| Scott | 8 | 1,062 | 1,074 | -0.09% | 48 | 22 | Town |
| Solon | 9 | 1,054 | 1,070 | 0% | 36 | 30 | Town |
| McGraw | 10 | 961 | 1,013 | -0.93% | 974 | 1 | Village |
| Truxton | 11 | 959 | 994 | -0.1% | 21 | 45 | Town |
| Cuyler | 12 | 889 | 913 | -0.34% | 20 | 43 | Town |
| Cincinnatus | 13 | 880 | 901 | -0.45% | 35 | 25 | Town |
| Willet | 14 | 869 | 894 | 0.12% | 34 | 26 | Town |
| Marathon | 15 | 866 | 913 | -0.92% | 766 | 1 | Village |
| Harford | 16 | 858 | 876 | -0.35% | 36 | 24 | Town |
| Lapeer | 17 | 787 | 790 | 0.25% | 31 | 25 | Town |
| Freetown | 18 | 750 | 768 | -0.66% | 29 | 25 | Town |
| Taylor | 19 | 423 | 444 | -0.7% | 14 | 30 | Town |
Cortland is the largest city in Cortland County, with a population of 17,390.
Taylor is the smallest city in Cortland County, with a population of 423.
There are 19 cities in Cortland County, New York.