31 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Warren | 1 | 8,955 | 9,380 | -0.94% | 3,076 | 2.91 | City |
| Conewango township | 2 | 3,316 | 3,420 | -0.51% | 111 | 29.96 | Township |
| Pleasant township | 3 | 2,176 | 2,246 | -0.55% | 65 | 33.69 | Township |
| Glade township | 4 | 1,964 | 2,036 | -0.61% | 55 | 36.02 | Township |
| North Warren | 5 | 1,919 | 2,008 | -0.05% | 234 | 8.19 | CDP |
| Sheffield township | 6 | 1,761 | 1,845 | -0.84% | 30 | 59.18 | Township |
| Brokenstraw township | 7 | 1,651 | 1,723 | -0.78% | 43 | 38.05 | Township |
| Youngsville | 8 | 1,647 | 1,726 | -0.96% | 1,238 | 1.33 | Borough |
| Sugar Grove township | 9 | 1,547 | 1,614 | -0.71% | 44 | 35.41 | Township |
| Columbus township | 10 | 1,543 | 1,600 | -0.64% | 38 | 40.63 | Township |
| Russell | 11 | 1,326 | 1,447 | -0.38% | 362 | 3.67 | CDP |
| Mead township | 12 | 1,257 | 1,295 | -0.48% | 16 | 78.63 | Township |
| Pittsfield township | 13 | 1,240 | 1,279 | -0.48% | 22 | 55.65 | Township |
| Freehold township | 14 | 1,159 | 1,210 | -0.77% | 32 | 35.74 | Township |
| Warren township | 15 | 1,026 | 1,021 | 0.2% | 24 | 42.53 | Township |
| Sugar Grove township | 16 | 909 | 951 | -0.98% | 73 | 12.39 | Township |
| Columbus | 17 | 858 | 898 | 0.23% | 379 | 2.27 | CDP |
| Spring Creek township | 18 | 743 | 774 | -0.67% | 15 | 48.69 | Township |
| Starbrick | 19 | 716 | 333 | 1.85% | 605 | 1.18 | CDP |
| Sheffield | 20 | 663 | 961 | -4.47% | 378 | 1.75 | CDP |
| Tidioute | 21 | 603 | 628 | -0.82% | 562 | 1.07 | Borough |
| Sugar Grove | 22 | 535 | 557 | -0.74% | 477 | 1.12 | Borough |
| Elk township | 23 | 462 | 479 | -0.65% | 11 | 41.02 | Township |
| Clarendon | 24 | 395 | 410 | -0.75% | 1,172 | 0.34 | Borough |
| Warren township | 25 | 342 | 326 | 1.79% | 11 | 30.63 | Township |
| Triumph township | 26 | 263 | 274 | -0.75% | 9 | 28.23 | Township |
| Deerfield township | 27 | 259 | 269 | -0.77% | 6 | 43.22 | Township |
| Watson township | 28 | 219 | 230 | -0.9% | 4 | 50.82 | Township |
| Spring Creek township | 29 | 192 | 198 | -0.52% | 3 | 63.63 | Township |
| Cherry Grove township | 30 | 166 | 173 | -0.6% | 4 | 46.27 | Township |
| Bear Lake | 31 | 144 | 148 | -0.69% | 209 | 0.69 | Borough |
Warren is the largest city in Warren County, with a population of 8,955.
Bear Lake is the smallest city in Warren County.
There are 31 cities in Warren County, Pennsylvania.