| City | County | 2026 Pop. ↓ |
|---|---|---|
| Kingston | Luzerne County | 13,491 |
| Kennett | Chester County | 9,273 |
| Kennedy | Allegheny County | 8,432 |
| Kingston | Luzerne County | 7,257 |
| Kennett Square | Chester County | 7,074 |
| Kiskiminetas | Armstrong County | 4,528 |
| Kutztown | Berks County | 4,267 |
| Kittanning | Armstrong County | 3,940 |
| Kelly | Union County | 3,536 |
| Kane | McKean County | 3,425 |
| Kenhorst | Berks County | 3,034 |
| Kulpmont | Northumberland County | 2,673 |
| Keating | McKean County | 2,611 |
| Kittanning | Armstrong County | 2,008 |
| Kidder | Carbon County | 1,867 |
| Kimmel | Bedford County | 1,506 |
| Kline | Schuylkill County | 1,485 |
| King | Bedford County | 1,171 |
| Knox | Clarion County | 1,061 |
| Knox | Clarion County | 977 |
| Knox | Clarion County | 976 |
| Kilbuck | Allegheny County | 737 |
| Koppel | Beaver County | 689 |
| Karthaus | Clearfield County | 673 |
| Knoxville | Tioga County | 662 |
| Knox | Clarion County | 579 |
| Kistler | Huntingdon County | 289 |
| Keating | Potter County | 282 |
| Kingsley | Susquehanna County | 249 |
| Karns City | Butler County | 158 |