26 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Warren | 1 | 9,058 | 9,393 | -0.73% | 3,112 | 3 | City |
| Conewango | 2 | 3,295 | 3,422 | -0.9% | 110 | 30 | Township |
| Pleasant | 3 | 2,170 | 2,249 | -0.82% | 64 | 34 | Township |
| Glade | 4 | 1,957 | 2,035 | -0.91% | 54 | 36 | Township |
| Sheffield | 5 | 1,754 | 1,846 | -1.18% | 30 | 59 | Township |
| Brokenstraw | 6 | 1,651 | 1,725 | -0.96% | 43 | 38 | Township |
| Youngsville | 7 | 1,647 | 1,726 | -0.96% | 1,238 | 1 | Borough |
| Sugar Grove | 8 | 1,546 | 1,614 | -0.83% | 44 | 35 | Township |
| Columbus | 9 | 1,543 | 1,602 | -0.84% | 38 | 41 | Township |
| Mead | 10 | 1,255 | 1,302 | -0.87% | 16 | 79 | Township |
| Pittsfield | 11 | 1,228 | 1,281 | -1.13% | 22 | 56 | Township |
| Freehold | 12 | 1,164 | 1,211 | -0.94% | 33 | 36 | Township |
| Warren | 13 | 1,019 | 1,020 | -0.1% | 24 | 43 | Township |
| Sugar Grove | 14 | 911 | 949 | -0.76% | 74 | 12 | Township |
| Spring Creek | 15 | 737 | 775 | -1.21% | 15 | 49 | Township |
| Tidioute | 16 | 603 | 627 | -0.82% | 562 | 1 | Borough |
| Sugar Grove | 17 | 533 | 556 | -0.93% | 475 | 1 | Borough |
| Elk | 18 | 458 | 480 | -1.29% | 11 | 41 | Township |
| Clarendon | 19 | 392 | 405 | -0.76% | 1,163 | 0 | Borough |
| Warren | 20 | 329 | 326 | -0.3% | 11 | 31 | Township |
| Triumph | 21 | 262 | 274 | -1.13% | 9 | 28 | Township |
| Deerfield | 22 | 254 | 265 | -1.17% | 6 | 43 | Township |
| Watson | 23 | 220 | 231 | -0.9% | 4 | 51 | Township |
| Spring Creek | 24 | 193 | 199 | -0.52% | 3 | 64 | Township |
| Cherry Grove | 25 | 164 | 172 | -1.2% | 4 | 46 | Township |
| Bear Lake | 26 | 141 | 149 | -1.4% | 204 | 1 | Borough |
Warren is the largest city in Warren County, with a population of 9,058.
Bear Lake is the smallest city in Warren County, with a population of 141.
There are 26 cities in Warren County, Pennsylvania.