26 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Warren | 1 | 8,991 | 9,393 | -0.74% | 3,089 | 3 | City |
| Conewango | 2 | 3,265 | 3,422 | -0.91% | 109 | 30 | Township |
| Pleasant | 3 | 2,152 | 2,249 | -0.83% | 64 | 34 | Township |
| Glade | 4 | 1,939 | 2,035 | -0.92% | 54 | 36 | Township |
| Sheffield | 5 | 1,733 | 1,846 | -1.2% | 29 | 59 | Township |
| Brokenstraw | 6 | 1,635 | 1,725 | -0.97% | 43 | 38 | Township |
| Youngsville | 7 | 1,631 | 1,726 | -0.97% | 1,226 | 1 | Borough |
| Sugar Grove | 8 | 1,533 | 1,614 | -0.84% | 43 | 35 | Township |
| Columbus | 9 | 1,530 | 1,602 | -0.84% | 38 | 41 | Township |
| Mead | 10 | 1,244 | 1,302 | -0.88% | 16 | 79 | Township |
| Pittsfield | 11 | 1,214 | 1,281 | -1.14% | 22 | 56 | Township |
| Freehold | 12 | 1,153 | 1,211 | -0.95% | 32 | 36 | Township |
| Warren | 13 | 1,018 | 1,020 | -0.1% | 24 | 43 | Township |
| Sugar Grove | 14 | 904 | 949 | -0.77% | 73 | 12 | Township |
| Spring Creek | 15 | 728 | 775 | -1.22% | 15 | 49 | Township |
| Tidioute | 16 | 598 | 627 | -0.83% | 557 | 1 | Borough |
| Sugar Grove | 17 | 529 | 556 | -0.75% | 472 | 1 | Borough |
| Elk | 18 | 452 | 480 | -1.31% | 11 | 41 | Township |
| Clarendon | 19 | 390 | 405 | -0.51% | 1,157 | 0 | Borough |
| Warren | 20 | 328 | 326 | -0.3% | 11 | 31 | Township |
| Triumph | 21 | 259 | 274 | -1.15% | 9 | 28 | Township |
| Deerfield | 22 | 251 | 265 | -1.18% | 6 | 43 | Township |
| Watson | 23 | 218 | 231 | -0.91% | 4 | 51 | Township |
| Spring Creek | 24 | 192 | 199 | -0.52% | 3 | 64 | Township |
| Cherry Grove | 25 | 162 | 172 | -1.22% | 4 | 46 | Township |
| Bear Lake | 26 | 140 | 149 | -0.71% | 203 | 1 | Borough |
Warren is the largest city in Warren County, with a population of 8,991.
Bear Lake is the smallest city in Warren County, with a population of 140.
There are 26 cities in Warren County, Pennsylvania.