| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Gloversville | 1 | 14,719 | 15,089 | -0.43% | 2,917 | 5 | City |
| Johnstown | 2 | 7,982 | 8,175 | -0.49% | 1,656 | 5 | City |
| Johnstown | 3 | 6,627 | 6,771 | 0.98% | 94 | 70 | Town |
| Mayfield | 4 | 6,078 | 6,129 | 0.08% | 104 | 58 | Town |
| Broadalbin | 5 | 5,085 | 5,137 | 0.16% | 160 | 32 | Town |
| Perth | 6 | 3,498 | 3,572 | -0.23% | 134 | 26 | Town |
| Northampton | 7 | 2,491 | 2,476 | 0.36% | 118 | 21 | Town |
| Oppenheim | 8 | 1,767 | 1,745 | 0.4% | 31 | 56 | Town |
| Ephratah | 9 | 1,640 | 1,670 | -0.3% | 42 | 39 | Town |
| Broadalbin | 10 | 1,321 | 1,359 | -0.6% | 977 | 1 | Village |
| Caroga | 11 | 1,244 | 1,241 | 0.48% | 25 | 51 | Town |
| Northville | 12 | 988 | 1,012 | -0.5% | 929 | 1 | Village |
| Mayfield | 13 | 763 | 788 | -0.65% | 758 | 1 | Village |
| Bleecker | 14 | 547 | 544 | 0.18% | 10 | 57 | Town |
| Stratford | 15 | 522 | 535 | -0.19% | 7.0 | 75 | Town |
Gloversville is the largest city in Fulton County, with a population of 14,719.
Stratford is the smallest city in Fulton County, with a population of 522.
There are 15 cities in Fulton County, New York.