20 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Cortland | 1 | 17,444 | 17,516 | -0.09% | 4,480 | 4 | City |
| Cortlandville | 2 | 8,174 | 8,402 | -0.22% | 164 | 50 | Town |
| Homer | 3 | 6,096 | 6,288 | -0.16% | 121 | 50 | Town |
| Homer | 4 | 3,049 | 3,182 | -0.88% | 1,584 | 2 | Village |
| Virgil | 5 | 2,382 | 2,427 | -0.21% | 50 | 47 | Town |
| Marathon | 6 | 1,962 | 2,036 | -0.41% | 79 | 25 | Town |
| Preble | 7 | 1,298 | 1,356 | -0.61% | 48 | 27 | Town |
| Scott | 8 | 1,058 | 1,074 | 0.09% | 48 | 22 | Town |
| Solon | 9 | 1,042 | 1,064 | 0.1% | 35 | 30 | Town |
| McGraw | 10 | 968 | 1,011 | -0.92% | 981 | 1 | Village |
| Truxton | 11 | 954 | 999 | -0.52% | 21 | 45 | Town |
| Cincinnatus | 12 | 890 | 902 | 0.45% | 35 | 25 | Town |
| Cuyler | 13 | 879 | 910 | -0.57% | 20 | 43 | Town |
| Marathon | 14 | 875 | 914 | -0.91% | 774 | 1 | Village |
| Willet | 15 | 864 | 894 | -0.23% | 34 | 26 | Town |
| Harford | 16 | 859 | 875 | -0.12% | 36 | 24 | Town |
| Lapeer | 17 | 794 | 794 | 1.28% | 32 | 25 | Town |
| Freetown | 18 | 756 | 766 | 0% | 30 | 25 | Town |
| Taylor | 19 | 430 | 448 | -0.46% | 14 | 30 | Town |
| Blodgett Mills | 20 | 200 | 212 | -3.38% | 92 | 2 | CDP |
Cortland is the largest city in Cortland County, with a population of 17,444.
Blodgett Mills is the smallest city in Cortland County, with a population of 200.
There are 20 cities in Cortland County, New York.