| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Warren | 1 | 8,972 | 9,384 | -0.82% | 3,082 | 3 | City |
| Conewango | 2 | 3,285 | 3,430 | -0.76% | 110 | 30 | Township |
| Pleasant | 3 | 2,147 | 2,247 | -0.79% | 64 | 34 | Township |
| Glade | 4 | 1,942 | 2,035 | -0.87% | 54 | 36 | Township |
| Sheffield | 5 | 1,736 | 1,846 | -1.08% | 29 | 59 | Township |
| Brokenstraw | 6 | 1,639 | 1,727 | -0.91% | 43 | 38 | Township |
| Youngsville | 7 | 1,621 | 1,724 | -1.1% | 1,219 | 1 | Borough |
| Columbus | 8 | 1,527 | 1,601 | -0.84% | 38 | 41 | Township |
| Sugar Grove | 9 | 1,527 | 1,613 | -0.97% | 43 | 35 | Township |
| Mead | 10 | 1,237 | 1,295 | -0.88% | 16 | 79 | Township |
| Pittsfield | 11 | 1,221 | 1,282 | -0.89% | 22 | 56 | Township |
| Freehold | 12 | 1,167 | 1,212 | -0.09% | 33 | 36 | Township |
| Warren | 13 | 1,018 | 1,022 | 0% | 24 | 43 | Township |
| Sugar Grove | 14 | 911 | 951 | -0.65% | 74 | 12 | Township |
| Spring Creek | 15 | 731 | 775 | -1.08% | 15 | 49 | Township |
| Tidioute | 16 | 594 | 624 | -0.83% | 554 | 1 | Borough |
| Sugar Grove | 17 | 523 | 549 | -0.76% | 467 | 1 | Borough |
| Elk | 18 | 459 | 480 | -0.65% | 11 | 41 | Township |
| Clarendon | 19 | 391 | 410 | -1.01% | 1,160 | 0 | Borough |
| Warren | 20 | 330 | 326 | 0% | 11 | 31 | Township |
| Triumph | 21 | 260 | 275 | -1.14% | 9.0 | 28 | Township |
| Deerfield | 22 | 255 | 267 | -0.78% | 6.0 | 43 | Township |
| Watson | 23 | 218 | 231 | -0.91% | 4.0 | 51 | Township |
| Spring Creek | 24 | 192 | 199 | -0.52% | 3.0 | 64 | Township |
| Cherry Grove | 25 | 165 | 173 | -0.6% | 4.0 | 46 | Township |
| Bear Lake | 26 | 139 | 148 | -1.42% | 201 | 1 | Borough |
Warren is the largest city in Warren County, with a population of 8,972.
Bear Lake is the smallest city in Warren County, with a population of 139.
There are 26 cities in Warren County, Pennsylvania.