34 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Hamilton township | 1 | 11,639 | 11,384 | 0.56% | 327 | 35.54 | Township |
| Hamilton township | 2 | 8,362 | 8,594 | -0.77% | 218 | 38.34 | Township |
| Punxsutawney | 3 | 5,511 | 5,766 | -0.92% | 1,637 | 3.37 | Borough |
| Brookville | 4 | 3,870 | 3,990 | -0.62% | 1,230 | 3.15 | Borough |
| Hamilton township | 5 | 2,806 | 2,711 | 0.83% | 208 | 13.50 | Township |
| Winslow township | 6 | 2,482 | 2,545 | -0.28% | 55 | 45.13 | Township |
| Reynoldsville | 7 | 2,462 | 2,547 | -0.69% | 1,774 | 1.39 | Borough |
| Snyder township | 8 | 2,305 | 2,366 | -0.3% | 56 | 41.07 | Township |
| Brockway | 9 | 2,210 | 2,279 | -0.63% | 1,865 | 1.19 | Borough |
| Coolspring township | 10 | 2,053 | 2,112 | -0.68% | 109 | 18.75 | Township |
| Bell township | 11 | 1,960 | 2,009 | -0.31% | 106 | 18.57 | Township |
| Henderson township | 12 | 1,900 | 1,940 | -0.16% | 87 | 21.94 | Township |
| Young township | 13 | 1,667 | 1,715 | -0.36% | 108 | 15.44 | Township |
| Warsaw township | 14 | 1,332 | 1,366 | -0.3% | 26 | 50.94 | Township |
| Pine Creek township | 15 | 1,300 | 1,325 | -0.23% | 46 | 28.31 | Township |
| Perry township | 16 | 1,214 | 1,248 | -0.33% | 43 | 28.43 | Township |
| Rose township | 17 | 1,126 | 1,153 | -0.27% | 59 | 19.09 | Township |
| McCalmont township | 18 | 1,107 | 1,136 | -0.36% | 42 | 26.25 | Township |
| Sykesville | 19 | 1,073 | 1,112 | -0.74% | 678 | 1.58 | Borough |
| Falls Creek | 20 | 1,001 | 1,033 | -0.6% | 1,074 | 0.93 | Borough |
| Union township | 21 | 829 | 849 | -0.24% | 47 | 17.59 | Township |
| Ringgold township | 22 | 756 | 772 | -0.13% | 40 | 19.11 | Township |
| Gaskill township | 23 | 662 | 676 | -0.15% | 31 | 21.38 | Township |
| Big Run | 24 | 625 | 644 | -0.64% | 904 | 0.69 | Borough |
| Hamilton township | 25 | 530 | 534 | 0% | 49 | 10.84 | Township |
| Hamilton township | 26 | 522 | 553 | -1.14% | 7 | 71.81 | Township |
| Summerville | 27 | 494 | 511 | -0.6% | 830 | 0.59 | Borough |
| Clover township | 28 | 420 | 429 | -0.24% | 26 | 15.94 | Township |
| Corsica | 29 | 309 | 319 | -0.64% | 682 | 0.45 | Borough |
| Porter township | 30 | 292 | 299 | -0.34% | 17 | 17.67 | Township |
| Barnett township | 31 | 227 | 231 | 0% | 16 | 14.58 | Township |
| Timblin | 32 | 139 | 144 | -0.71% | 154 | 0.90 | Borough |
| Heath township | 33 | 115 | 117 | 0% | 4 | 27.65 | Township |
| Worthville | 34 | 69 | 73 | -1.43% | 385 | 0.18 | Borough |
Hamilton township is the largest city in Jefferson County, with a population of 11,639.
Worthville is the smallest city in Jefferson County.
There are 34 cities in Jefferson County, Pennsylvania.