81 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Peters | 1 | 23,190 | 22,953 | -0.12% | 1,189 | 20 | Township |
| North Strabane | 2 | 17,669 | 15,767 | 1.66% | 648 | 27 | Township |
| Washington | 3 | 15,417 | 14,869 | 0.02% | 395 | 39 | Township |
| Cecil | 4 | 15,196 | 14,656 | 0.26% | 577 | 26 | Township |
| Amity | 5 | 13,767 | 13,358 | 0.73% | 761 | 18 | Township |
| Washington | 6 | 13,430 | 13,142 | 0.36% | 4,585 | 3 | City |
| South Strabane | 7 | 9,568 | 9,652 | -0.22% | 416 | 23 | Township |
| Canonsburg | 8 | 9,525 | 9,752 | -0.4% | 4,123 | 2 | Borough |
| Chartiers | 9 | 9,357 | 8,681 | 0.66% | 380 | 25 | Township |
| Lawrence | 10 | 7,272 | 7,494 | -0.36% | 88 | 83 | Township |
| Washington | 11 | 6,826 | 6,542 | 1.07% | 290 | 24 | Township |
| Washington | 12 | 6,821 | 6,878 | 0.07% | 213 | 32 | Township |
| Union | 13 | 5,640 | 5,387 | 1.33% | 369 | 15 | Township |
| Carroll | 14 | 5,256 | 5,380 | -0.42% | 390 | 13 | Township |
| Washington | 15 | 5,238 | 5,148 | 0.46% | 294 | 18 | Township |
| North Franklin | 16 | 4,702 | 4,821 | -0.47% | 641 | 7 | Township |
| Washington | 17 | 4,639 | 4,462 | 0.74% | 330 | 14 | Township |
| Donora | 18 | 4,441 | 4,563 | -0.45% | 2,339 | 2 | Borough |
| Washington | 19 | 4,382 | 4,390 | 0.02% | 97 | 45 | Township |
| California | 20 | 4,260 | 5,363 | -4.14% | 387 | 11 | Borough |
| Smith | 21 | 4,200 | 4,233 | -0.05% | 122 | 34 | Township |
| Charleroi | 22 | 4,121 | 4,235 | -0.46% | 5,408 | 1 | Borough |
| Monongahela | 23 | 4,034 | 4,147 | -0.47% | 2,109 | 2 | City |
| Fallowfield | 24 | 3,991 | 4,099 | -0.4% | 188 | 21 | Township |
| Amwell | 25 | 3,651 | 3,679 | -0.05% | 81 | 45 | Township |
| Washington | 26 | 3,620 | 3,879 | -1.01% | 365 | 10 | Township |
| Washington | 27 | 3,176 | 3,128 | 0.35% | 102 | 31 | Township |
| South Franklin | 28 | 2,824 | 2,874 | -0.28% | 137 | 21 | Township |
| Washington | 29 | 2,702 | 2,581 | 1.2% | 96 | 28 | Township |
| Bentleyville | 30 | 2,320 | 2,365 | -0.3% | 628 | 4 | Borough |
| Hickory | 31 | 2,271 | 2,319 | -0.31% | 143 | 16 | Township |
| East Bethlehem | 32 | 2,234 | 2,296 | -0.53% | 441 | 5 | Township |
| Washington | 33 | 2,142 | 2,130 | 0.23% | 121 | 18 | Township |
| New Eagle | 34 | 2,000 | 2,054 | -0.45% | 1,969 | 1 | Borough |
| Buffalo | 35 | 1,948 | 1,980 | -0.1% | 96 | 20 | Township |
| Washington | 36 | 1,835 | 1,861 | -0.16% | 56 | 33 | Township |
| Washington | 37 | 1,827 | 1,892 | -0.6% | 38 | 48 | Township |
| East Washington | 38 | 1,805 | 1,852 | -0.44% | 4,020 | 0 | Borough |
| Washington | 39 | 1,790 | 1,767 | 0.79% | 37 | 48 | Township |
| Washington | 40 | 1,774 | 1,750 | 0.06% | 74 | 24 | Township |
| Washington | 41 | 1,646 | 1,647 | 0.06% | 43 | 38 | Township |
| Lawrence | 42 | 1,609 | 1,611 | 0.06% | 47 | 34 | Township |
| North Bethlehem | 43 | 1,542 | 1,563 | -0.13% | 70 | 22 | Township |
| West Pike Run | 44 | 1,503 | 1,544 | -0.46% | 92 | 16 | Township |
| Independence | 45 | 1,480 | 1,510 | -0.47% | 57 | 26 | Township |
| Burgettstown | 46 | 1,388 | 1,426 | -0.43% | 2,232 | 1 | Borough |
| Monongahela | 47 | 1,370 | 1,481 | -1.58% | 79 | 17 | Township |
| Cross Creek | 48 | 1,349 | 1,373 | -0.44% | 49 | 28 | Township |
| Washington | 49 | 1,291 | 1,336 | -0.69% | 68 | 19 | Township |
| East Finley | 50 | 1,284 | 1,288 | 0.23% | 37 | 35 | Township |
| North Charleroi | 51 | 1,267 | 1,303 | -0.47% | 4,930 | 0 | Borough |
| West Bethlehem | 52 | 1,260 | 1,291 | -0.47% | 56 | 22 | Township |
| Washington | 53 | 1,233 | 1,287 | -0.64% | 49 | 25 | Township |
| Houston | 54 | 1,140 | 1,172 | -0.44% | 2,774 | 0 | Borough |
| Amity | 55 | 981 | 982 | 0.2% | 35 | 28 | Township |
| Midway | 56 | 909 | 923 | -0.22% | 2,066 | 0 | Borough |
| Ellsworth | 57 | 893 | 919 | -0.45% | 1,208 | 1 | Borough |
| Washington | 58 | 866 | 926 | -1.14% | 32 | 27 | Township |
| Washington | 59 | 865 | 844 | 0% | 65 | 13 | Township |
| Washington | 60 | 856 | 894 | -0.58% | 38 | 22 | Township |
| West Finley | 61 | 836 | 810 | 0.36% | 21 | 39 | Township |
| Washington | 62 | 769 | 750 | 0.52% | 43 | 18 | Township |
| Claysville | 63 | 712 | 730 | -0.42% | 2,304 | 0 | Borough |
| Washington | 64 | 696 | 710 | 0.14% | 43 | 16 | Township |
| Roscoe | 65 | 696 | 717 | -0.43% | 3,824 | 0 | Borough |
| Blaine | 66 | 608 | 620 | -0.49% | 51 | 12 | Township |
| Cokeburg | 67 | 603 | 620 | -0.5% | 1,713 | 0 | Borough |
| Allenport | 68 | 469 | 484 | -0.42% | 220 | 2 | Borough |
| Stockdale | 69 | 412 | 423 | -0.48% | 1,597 | 0 | Borough |
| Long Branch | 70 | 409 | 420 | -0.49% | 128 | 3 | Borough |
| Marianna | 71 | 384 | 396 | -0.52% | 196 | 2 | Borough |
| Beallsville | 72 | 382 | 393 | -0.52% | 157 | 2 | Borough |
| Hickory | 73 | 375 | 412 | -2.34% | 10 | 38 | Township |
| Finleyville | 74 | 365 | 374 | -0.27% | 2,186 | 0 | Borough |
| Dunlevy | 75 | 364 | 370 | -0.27% | 684 | 1 | Borough |
| Daisytown | 76 | 280 | 291 | -0.71% | 1,202 | 0 | Borough |
| Elco | 77 | 254 | 263 | -0.39% | 910 | 0 | Borough |
| Twilight | 78 | 219 | 225 | -0.45% | 136 | 2 | Borough |
| West Middletown | 79 | 108 | 108 | 0% | 266 | 0 | Borough |
| Coal Center | 80 | 106 | 108 | 0% | 930 | 0 | Borough |
| Green Hills | 81 | 19 | 19 | 0% | 21 | 1 | Borough |
Peters is the largest city in Washington County, with a population of 23,190.
Green Hills is the smallest city in Washington County, with a population of 19.
There are 81 cities in Washington County, Pennsylvania.