20 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Cortland | 1 | 17,116 | 17,515 | -0.47% | 4,395 | 3.89 | City |
| Cortlandville | 2 | 8,096 | 8,403 | -0.65% | 163 | 49.72 | Town |
| Homer | 3 | 5,985 | 6,289 | -0.96% | 119 | 50.22 | Town |
| Homer | 4 | 3,006 | 3,183 | -1.15% | 1,562 | 1.93 | Village |
| Virgil | 5 | 2,380 | 2,424 | -0.13% | 50 | 47.37 | Town |
| Marathon | 6 | 1,932 | 2,032 | -0.97% | 77 | 24.94 | Town |
| Preble | 7 | 1,292 | 1,357 | -0.77% | 48 | 26.84 | Town |
| Scott | 8 | 1,040 | 1,074 | -0.67% | 47 | 22.24 | Town |
| Solon | 9 | 1,016 | 1,064 | -1.07% | 34 | 29.65 | Town |
| McGraw | 10 | 955 | 1,010 | -1.14% | 968 | 0.99 | Village |
| Truxton | 11 | 935 | 998 | -1.37% | 21 | 44.65 | Town |
| Cuyler | 12 | 870 | 909 | -1.02% | 20 | 43.48 | Town |
| Marathon | 13 | 863 | 913 | -1.15% | 764 | 1.13 | Village |
| Cincinnatus | 14 | 862 | 902 | -1.03% | 34 | 25.36 | Town |
| Willet | 15 | 849 | 894 | -1.05% | 33 | 25.73 | Town |
| Harford | 16 | 845 | 874 | -0.82% | 35 | 24.15 | Town |
| Lapeer | 17 | 759 | 793 | -0.78% | 30 | 25.04 | Town |
| Freetown | 18 | 746 | 765 | -0.53% | 29 | 25.49 | Town |
| Taylor | 19 | 425 | 448 | -0.93% | 14 | 30 | Town |
| Blodgett Mills | 20 | 200 | 212 | -3.38% | 92 | 2.17 | CDP |
Cortland is the largest city in Cortland County, with a population of 17,116.
Blodgett Mills is the smallest city in Cortland County, with a population of 200.
There are 20 cities in Cortland County, New York.