| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Batavia | 1 | 15,182 | 15,163 | 0.09% | 2,922 | 5 | City |
| Le Roy | 2 | 7,529 | 7,651 | -0.63% | 179 | 42 | Town |
| Batavia | 3 | 7,243 | 6,672 | 2.07% | 150 | 48 | Town |
| Pembroke | 4 | 4,333 | 4,266 | 0.96% | 104 | 42 | Town |
| Le Roy | 5 | 4,281 | 4,387 | -0.35% | 1,591 | 3 | Village |
| Bergen | 6 | 3,115 | 3,120 | -0.16% | 113 | 28 | Town |
| Oakfield | 7 | 3,079 | 3,144 | -0.52% | 132 | 23 | Town |
| Darien | 8 | 2,973 | 3,008 | -0.4% | 63 | 47 | Town |
| Alexander | 9 | 2,440 | 2,472 | -0.25% | 69 | 35 | Town |
| Stafford | 10 | 2,368 | 2,426 | -0.75% | 76 | 31 | Town |
| Byron | 11 | 2,268 | 2,299 | -0.35% | 70 | 32 | Town |
| Pavilion | 12 | 2,244 | 2,281 | -0.44% | 63 | 36 | Town |
| Elba | 13 | 2,126 | 2,153 | -0.42% | 60 | 36 | Town |
| Oakfield | 14 | 1,789 | 1,824 | -0.28% | 2,707 | 1 | Village |
| Bethany | 15 | 1,739 | 1,781 | -0.57% | 48 | 36 | Town |
| Alabama | 16 | 1,590 | 1,622 | -0.38% | 38 | 42 | Town |
| Bergen | 17 | 1,244 | 1,237 | 0.16% | 1,688 | 1 | Village |
| Corfu | 18 | 726 | 709 | 0.28% | 730 | 1 | Village |
| Elba | 19 | 590 | 603 | -0.34% | 580 | 1 | Village |
| Alexander | 20 | 486 | 501 | -0.61% | 1,112 | 0 | Village |
Batavia is the largest city in Genesee County, with a population of 15,182.
Alexander is the smallest city in Genesee County, with a population of 486.
There are 20 cities in Genesee County, New York.