Founded in 1804, Seneca County is one of 62 counties in the state of New York. Historically, Seneca County was formed from Cayuga County. The city of Waterloo is the county seat. With FIPS code of 99, Seneca County has a population of 33,688 and area of 325 square miles (842 km2).
List of all cities in Seneca County, NY alphabetically
| City/Town | Postal Code | Area Code |
| Canoga, NY | 13148 | 315 |
| Fayette, NY | 13065 | 315 |
| Hayt Corners, NY | 14521 | 607 |
| Interlaken, NY | 14847 | 607 |
| Junius, NY | 13165 | 315 |
| Lodi, NY | 14860 | 607 |
| Mac Dougall, NY | 14541 | 315 |
| Ovid, NY | 14521 | 607 |
| Romulus, NY | 14541 | 315 |
| Seneca Falls, NY | 13148 | 315 |
| Tyre, NY | 13148 | 315 |
| Waterloo, NY | 13165 | 315 |
| Willard, NY | 14588 | 607 |