110 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Peters | 1 | 23,219 | 22,953 | -0.12% | 1,191 | 20 | Township |
| North Strabane | 2 | 17,381 | 15,767 | 1.68% | 638 | 27 | Township |
| Washington | 3 | 15,414 | 14,869 | 0.02% | 394 | 39 | Township |
| Cecil | 4 | 15,157 | 14,656 | 0.26% | 575 | 26 | Township |
| Amity | 5 | 13,667 | 13,358 | 0.74% | 756 | 18 | Township |
| Washington | 6 | 13,382 | 13,142 | 0.36% | 4,569 | 3 | City |
| South Strabane | 7 | 9,589 | 9,652 | -0.22% | 417 | 23 | Township |
| Canonsburg | 8 | 9,563 | 9,752 | -0.4% | 4,140 | 2 | Borough |
| Chartiers | 9 | 9,296 | 8,681 | 0.66% | 378 | 25 | Township |
| Lawrence | 10 | 7,298 | 7,494 | -0.35% | 88 | 83 | Township |
| Washington | 11 | 6,816 | 6,878 | 0.07% | 213 | 32 | Township |
| Washington | 12 | 6,754 | 6,542 | 1.08% | 287 | 24 | Township |
| Union | 13 | 5,566 | 5,387 | 1.35% | 364 | 15 | Township |
| Carroll | 14 | 5,278 | 5,380 | -0.42% | 392 | 13 | Township |
| Washington | 15 | 5,214 | 5,148 | 0.46% | 292 | 18 | Township |
| North Franklin | 16 | 4,724 | 4,821 | -0.46% | 644 | 7 | Township |
| Washington | 17 | 4,605 | 4,462 | 0.74% | 327 | 14 | Township |
| McGovern | 18 | 4,557 | 3,209 | 2.73% | 1,979 | 2 | CDP |
| Donora | 19 | 4,461 | 4,563 | -0.47% | 2,349 | 2 | Borough |
| California | 20 | 4,444 | 5,363 | -3.98% | 404 | 11 | Borough |
| Washington | 21 | 4,381 | 4,390 | 0.02% | 97 | 45 | Township |
| Smith | 22 | 4,202 | 4,233 | -0.05% | 122 | 34 | Township |
| Charleroi | 23 | 4,140 | 4,235 | -0.46% | 5,433 | 1 | Borough |
| Monongahela | 24 | 4,053 | 4,147 | -0.47% | 2,119 | 2 | City |
| McMurray | 25 | 4,034 | 4,167 | -1.01% | 1,315 | 3 | CDP |
| Fallowfield | 26 | 4,007 | 4,099 | -0.4% | 188 | 21 | Township |
| Thompsonville | 27 | 3,944 | 3,631 | 0.72% | 1,906 | 2 | CDP |
| Washington | 28 | 3,657 | 3,879 | -1% | 368 | 10 | Township |
| Amwell | 29 | 3,653 | 3,679 | -0.05% | 82 | 45 | Township |
| Washington | 30 | 3,165 | 3,128 | 0.35% | 102 | 31 | Township |
| Wolfdale | 31 | 3,096 | 3,097 | 0.45% | 1,169 | 3 | CDP |
| South Franklin | 32 | 2,832 | 2,874 | -0.28% | 138 | 21 | Township |
| Washington | 33 | 2,670 | 2,581 | 1.21% | 95 | 28 | Township |
| Gastonville | 34 | 2,514 | 2,656 | -0.79% | 922 | 3 | CDP |
| Muse | 35 | 2,500 | 2,483 | 0% | 1,611 | 2 | CDP |
| Bentleyville | 36 | 2,327 | 2,365 | -0.34% | 630 | 4 | Borough |
| Hickory | 37 | 2,278 | 2,319 | -0.31% | 144 | 16 | Township |
| East Bethlehem | 38 | 2,246 | 2,296 | -0.53% | 443 | 5 | Township |
| Washington | 39 | 2,137 | 2,130 | 0.23% | 121 | 18 | Township |
| New Eagle | 40 | 2,009 | 2,054 | -0.45% | 1,977 | 1 | Borough |
| Buffalo | 41 | 1,950 | 1,980 | -0.1% | 96 | 20 | Township |
| Washington | 42 | 1,838 | 1,861 | -0.16% | 56 | 33 | Township |
| Washington | 43 | 1,838 | 1,892 | -0.59% | 39 | 48 | Township |
| East Washington | 44 | 1,813 | 1,852 | -0.44% | 4,038 | 0 | Borough |
| Washington | 45 | 1,776 | 1,767 | 0.79% | 37 | 48 | Township |
| Washington | 46 | 1,773 | 1,750 | 0.06% | 74 | 24 | Township |
| Washington | 47 | 1,645 | 1,647 | 0.06% | 43 | 38 | Township |
| Lawrence | 48 | 1,608 | 1,611 | 0.06% | 47 | 34 | Township |
| North Bethlehem | 49 | 1,544 | 1,563 | -0.13% | 70 | 22 | Township |
| West Pike Run | 50 | 1,510 | 1,544 | -0.46% | 93 | 16 | Township |
| Independence | 51 | 1,487 | 1,510 | -0.47% | 58 | 26 | Township |
| Burgettstown | 52 | 1,394 | 1,426 | -0.5% | 2,241 | 1 | Borough |
| Monongahela | 53 | 1,392 | 1,481 | -1.56% | 80 | 17 | Township |
| Cross Creek | 54 | 1,355 | 1,373 | -0.44% | 49 | 28 | Township |
| Wickerham Manor-Fisher | 55 | 1,316 | 1,510 | -2.01% | 621 | 2 | CDP |
| Washington | 56 | 1,300 | 1,336 | -0.69% | 69 | 19 | Township |
| East Finley | 57 | 1,281 | 1,288 | 0.23% | 36 | 35 | Township |
| North Charleroi | 58 | 1,273 | 1,303 | -0.47% | 4,953 | 0 | Borough |
| West Bethlehem | 59 | 1,266 | 1,291 | -0.47% | 56 | 22 | Township |
| Washington | 60 | 1,241 | 1,287 | -0.64% | 50 | 25 | Township |
| Houston | 61 | 1,145 | 1,172 | -0.52% | 2,786 | 0 | Borough |
| Lawrence | 62 | 1,119 | 874 | 3.61% | 2,826 | 0 | CDP |
| Amity | 63 | 979 | 982 | 0.2% | 35 | 28 | Township |
| Midway | 64 | 911 | 923 | -0.33% | 2,070 | 0 | Borough |
| Ellsworth | 65 | 897 | 919 | -0.55% | 1,214 | 1 | Borough |
| Washington | 66 | 876 | 926 | -1.13% | 32 | 27 | Township |
| Washington | 67 | 865 | 844 | 0% | 65 | 13 | Township |
| Washington | 68 | 861 | 894 | -0.58% | 38 | 22 | Township |
| West Finley | 69 | 833 | 810 | 0.36% | 21 | 39 | Township |
| Avella | 70 | 796 | 920 | -0.13% | 883 | 1 | CDP |
| Washington | 71 | 765 | 750 | 0.53% | 42 | 18 | Township |
| Claysville | 72 | 715 | 730 | -0.42% | 2,314 | 0 | Borough |
| Roscoe | 73 | 699 | 717 | -0.57% | 3,841 | 0 | Borough |
| Washington | 74 | 695 | 710 | 0.14% | 43 | 16 | Township |
| Eighty Four | 75 | 652 | 345 | 0% | 99 | 7 | CDP |
| Blaine | 76 | 611 | 620 | -0.49% | 51 | 12 | Township |
| Hickory | 77 | 610 | 542 | -1.45% | 214 | 3 | CDP |
| Cokeburg | 78 | 606 | 620 | -0.49% | 1,722 | 0 | Borough |
| Atlasburg | 79 | 595 | 545 | 2.23% | 883 | 1 | CDP |
| Allenport | 80 | 572 | 564 | -0.87% | 590 | 1 | CDP |
| Wylandville | 81 | 564 | 539 | 2.17% | 384 | 1 | CDP |
| Van Voorhis | 82 | 544 | 478 | 5.02% | 1,432 | 0 | CDP |
| Slovan | 83 | 506 | 559 | -0.78% | 862 | 1 | CDP |
| Langeloth | 84 | 498 | 707 | -2.92% | 478 | 1 | CDP |
| Midway | 85 | 486 | 935 | -18.46% | 1,464 | 0 | CDP |
| Allenport | 86 | 471 | 484 | -0.63% | 221 | 2 | Borough |
| Stockdale | 87 | 414 | 423 | -0.48% | 1,605 | 0 | Borough |
| Long Branch | 88 | 411 | 420 | -0.48% | 129 | 3 | Borough |
| Marianna | 89 | 386 | 396 | -0.52% | 197 | 2 | Borough |
| Southview | 90 | 386 | 314 | 1.85% | 426 | 1 | CDP |
| Beallsville | 91 | 384 | 393 | -0.52% | 158 | 2 | Borough |
| Hickory | 92 | 384 | 412 | -2.29% | 10 | 38 | Township |
| West Alexander | 93 | 374 | 412 | -3.86% | 306 | 1 | CDP |
| Finleyville | 94 | 366 | 374 | -0.54% | 2,192 | 0 | Borough |
| Dunlevy | 95 | 365 | 370 | -0.27% | 686 | 1 | Borough |
| Joffre | 96 | 362 | 410 | -3.21% | 404 | 1 | CDP |
| Bulger | 97 | 291 | 412 | -2.35% | 202 | 1 | CDP |
| Daisytown | 98 | 282 | 291 | -0.7% | 1,210 | 0 | Borough |
| Taylorstown | 99 | 273 | 260 | 1.11% | 259 | 1 | CDP |
| Fredericktown | 100 | 269 | 200 | -3.24% | 278 | 1 | CDP |
| Elco | 101 | 255 | 263 | -0.78% | 914 | 0 | Borough |
| Elrama | 102 | 233 | 470 | -2.1% | 1,596 | 0 | CDP |
| Millsboro | 103 | 221 | 503 | -11.95% | 280 | 1 | CDP |
| Twilight | 104 | 220 | 225 | -0.45% | 137 | 2 | Borough |
| Hendersonville | 105 | 108 | 145 | -11.48% | 271 | 0 | CDP |
| West Middletown | 106 | 108 | 108 | 0% | 266 | 0 | Borough |
| Coal Center | 107 | 106 | 108 | -0.93% | 930 | 0 | Borough |
| Meadowlands | 108 | 31 | 680 | -63.1% | 35 | 1 | CDP |
| Green Hills | 109 | 19 | 19 | 0% | 21 | 1 | Borough |
| Westland | 110 | 7 | 45 | -61.11% | 42 | 0 | CDP |
Peters is the largest city in Washington County, with a population of 23,219.
Westland is the smallest city in Washington County, with a population of 7.
There are 110 cities in Washington County, Pennsylvania.