Founded in 1805, Lewis County is one of 62 counties in the state of New York. Historically, Lewis County was formed from Oneida County. The city of Lowville is the county seat. With FIPS code of 49, Lewis County has a population of 26,573 and area of 1,290 square miles (3,341 km2).
List of all cities in Lewis County, NY alphabetically
| City/Town | Postal Code | Area Code |
| Barnes Corners, NY | 13626 | 315 |
| Beaver Falls, NY | 13305 | 315 |
| Beaver River, NY | 13367 | 315 |
| Belfort, NY | 13327 | 315 |
| Brantingham, NY | 13312 | 315 |
| Castorland, NY | 13620 | 315 |
| Chase Lake, NY | 13343 | 315 |
| Collinsville, NY | 13433 | 315 |
| Constableville, NY | 13325 | 315 |
| Copenhagen, NY | 13626 | 315 |
| Croghan, NY | 13327 | 315 |
| Dadville, NY | 13367 | 315 |
| Deer River, NY | 13627 | 315 |
| Denmark, NY | 13631 | 315 |
| Diana, NY | 13648 | 315 |
| East Pitcairn, NY | 13648 | 315 |
| Fish Creek, NY | 13325 | 315 |
| Fowlersville, NY | 13433 | 315 |
| Geers Corners, NY | 13648 | 315 |
| Glenfield, NY | 13312 | 315 |
| 13343 | 315 | |
| 13345 | 315 | |
| Goulds Mill, NY | 13368 | 315 |
| Greig, NY | 13345 | 315 |
| Harrisburg, NY | 13367 | 315 |
| Harrisville, NY | 13648 | 315 |
| Houseville, NY | 13473 | 315 |
| Indian River, NY | 13327 | 315 |
| Kirschnerville, NY | 13327 | 315 |
| Lake Bonaparte, NY | 13648 | 315 |
| Leyden, NY | 13433 | 315 |
| Lowville, NY | 13367 | 315 |
| Lyons Falls, NY | 13368 | 315 |
| Lyonsdale, NY | 13368 | 315 |
| Martinsburg, NY | 13404 | 315 |
| Montague, NY | 13367 | 315 |
| Moose River, NY | 13433 | 315 |
| New Breman, NY | 13367 | 315 |
| Otter Creek, NY | 13343 | 315 |
| Pine Grove, NY | 13343 | 315 |
| Pitcairn, NY | 13648 | 315 |
| Port Leyden, NY | 13433 | 315 |
| South Rutland, NY | 13626 | 315 |
| Turin, NY | 13473 | 315 |
| Watson, NY | 13367 | 315 |
| West Leyden, NY | 13489 | 315 |
| West Lowville, NY | 13367 | 315 |
| West Turin, NY | 13325 | 315 |