110 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Peters | 1 | 23,272 | 22,958 | 0.02% | 1,193 | 20 | Township |
| North Strabane | 2 | 17,565 | 15,690 | 2.47% | 644 | 27 | Township |
| Washington | 3 | 15,828 | 14,867 | 1.39% | 405 | 39 | Township |
| Cecil | 4 | 15,337 | 14,651 | 0.89% | 582 | 26 | Township |
| Washington | 5 | 13,607 | 13,162 | 0.66% | 4,646 | 3 | City |
| Amity | 6 | 13,469 | 13,392 | 0.19% | 745 | 18 | Township |
| Canonsburg | 7 | 9,549 | 9,748 | -0.42% | 4,134 | 2 | Borough |
| South Strabane | 8 | 9,548 | 9,640 | -0.33% | 415 | 23 | Township |
| Chartiers | 9 | 9,222 | 8,679 | 0.29% | 375 | 25 | Township |
| Lawrence | 10 | 7,225 | 7,500 | -0.84% | 88 | 83 | Township |
| Washington | 11 | 6,753 | 6,878 | -0.34% | 211 | 32 | Township |
| Washington | 12 | 6,557 | 6,544 | -0.02% | 278 | 24 | Township |
| Union | 13 | 5,526 | 5,384 | 1.01% | 361 | 15 | Township |
| Carroll | 14 | 5,277 | 5,380 | -0.36% | 391 | 13 | Township |
| Washington | 15 | 5,155 | 5,145 | 0.04% | 289 | 18 | Township |
| North Franklin | 16 | 4,733 | 4,824 | -0.36% | 645 | 7 | Township |
| McGovern | 17 | 4,557 | 3,209 | 2.73% | 1,979 | 2 | CDP |
| Washington | 18 | 4,541 | 4,464 | 0.22% | 323 | 14 | Township |
| Donora | 19 | 4,459 | 4,561 | -0.45% | 2,348 | 2 | Borough |
| Washington | 20 | 4,343 | 4,392 | -0.37% | 96 | 45 | Township |
| Smith | 21 | 4,168 | 4,233 | -0.36% | 121 | 34 | Township |
| California | 22 | 4,157 | 5,361 | -5.48% | 378 | 11 | Borough |
| Charleroi | 23 | 4,133 | 4,235 | -0.48% | 5,424 | 1 | Borough |
| Monongahela | 24 | 4,047 | 4,147 | -0.49% | 2,116 | 2 | City |
| McMurray | 25 | 4,034 | 4,167 | -1.01% | 1,315 | 3 | CDP |
| Fallowfield | 26 | 4,004 | 4,100 | -0.42% | 188 | 21 | Township |
| Thompsonville | 27 | 3,944 | 3,631 | 0.72% | 1,906 | 2 | CDP |
| Amwell | 28 | 3,635 | 3,682 | -0.3% | 81 | 45 | Township |
| Washington | 29 | 3,605 | 3,888 | -1.5% | 363 | 10 | Township |
| Washington | 30 | 3,154 | 3,124 | 0.25% | 102 | 31 | Township |
| Wolfdale | 31 | 3,096 | 3,097 | 0.45% | 1,169 | 3 | CDP |
| South Franklin | 32 | 2,818 | 2,871 | -0.35% | 137 | 21 | Township |
| Washington | 33 | 2,618 | 2,579 | 0.34% | 93 | 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 | 2,315 | 2,355 | -0.34% | 627 | 4 | Borough |
| Hickory | 37 | 2,285 | 2,316 | -0.04% | 144 | 16 | Township |
| East Bethlehem | 38 | 2,270 | 2,312 | -0.35% | 448 | 5 | Township |
| Washington | 39 | 2,094 | 2,130 | -0.48% | 118 | 18 | Township |
| New Eagle | 40 | 2,002 | 2,057 | -0.55% | 1,970 | 1 | Borough |
| Buffalo | 41 | 1,947 | 1,983 | -0.26% | 96 | 20 | Township |
| Washington | 42 | 1,846 | 1,892 | -0.27% | 39 | 48 | Township |
| Washington | 43 | 1,813 | 1,863 | -0.71% | 55 | 33 | Township |
| Washington | 44 | 1,813 | 1,753 | 1.17% | 76 | 24 | Township |
| East Washington | 45 | 1,809 | 1,851 | -0.44% | 4,029 | 0 | Borough |
| Washington | 46 | 1,728 | 1,768 | -0.46% | 36 | 48 | Township |
| Washington | 47 | 1,650 | 1,648 | 0.18% | 43 | 38 | Township |
| Lawrence | 48 | 1,591 | 1,611 | -0.31% | 46 | 34 | Township |
| North Bethlehem | 49 | 1,521 | 1,551 | -0.39% | 69 | 22 | Township |
| West Pike Run | 50 | 1,509 | 1,543 | -0.4% | 93 | 16 | Township |
| Independence | 51 | 1,491 | 1,510 | -0.2% | 58 | 26 | Township |
| Monongahela | 52 | 1,426 | 1,485 | -0.42% | 82 | 17 | Township |
| Burgettstown | 53 | 1,388 | 1,425 | -0.5% | 2,232 | 1 | Borough |
| Cross Creek | 54 | 1,374 | 1,373 | 0.29% | 50 | 28 | Township |
| Wickerham Manor-Fisher | 55 | 1,316 | 1,510 | -2.01% | 621 | 2 | CDP |
| Washington | 56 | 1,296 | 1,336 | -0.84% | 68 | 19 | Township |
| East Finley | 57 | 1,280 | 1,288 | 0.16% | 36 | 35 | Township |
| North Charleroi | 58 | 1,268 | 1,302 | -0.55% | 4,934 | 0 | Borough |
| West Bethlehem | 59 | 1,260 | 1,291 | -0.55% | 56 | 22 | Township |
| Washington | 60 | 1,242 | 1,286 | -0.48% | 50 | 25 | Township |
| Houston | 61 | 1,140 | 1,169 | -0.52% | 2,774 | 0 | Borough |
| Lawrence | 62 | 1,119 | 874 | 3.61% | 2,826 | 0 | CDP |
| Amity | 63 | 968 | 980 | -0.21% | 35 | 28 | Township |
| Ellsworth | 64 | 915 | 940 | -0.54% | 1,238 | 1 | Borough |
| Midway | 65 | 909 | 923 | -0.33% | 2,066 | 0 | Borough |
| Washington | 66 | 885 | 927 | -0.45% | 33 | 27 | Township |
| Washington | 67 | 876 | 845 | 0.57% | 66 | 13 | Township |
| West Finley | 68 | 859 | 813 | 1.78% | 22 | 39 | Township |
| Washington | 69 | 856 | 895 | -1.04% | 38 | 22 | Township |
| Avella | 70 | 796 | 920 | -0.13% | 883 | 1 | CDP |
| Washington | 71 | 782 | 748 | 1.56% | 43 | 18 | Township |
| Claysville | 72 | 712 | 729 | -0.42% | 2,304 | 0 | Borough |
| Roscoe | 73 | 699 | 719 | -0.57% | 3,841 | 0 | Borough |
| Washington | 74 | 680 | 710 | -0.87% | 42 | 16 | Township |
| Eighty Four | 75 | 652 | 345 | 0% | 99 | 7 | CDP |
| Cokeburg | 76 | 611 | 626 | -0.49% | 1,736 | 0 | Borough |
| Hickory | 77 | 610 | 542 | -1.45% | 214 | 3 | CDP |
| Blaine | 78 | 610 | 620 | -0.49% | 51 | 12 | Township |
| 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 | 473 | 485 | -0.42% | 222 | 2 | Borough |
| Stockdale | 87 | 414 | 424 | -0.48% | 1,605 | 0 | Borough |
| Long Branch | 88 | 410 | 420 | -0.49% | 129 | 3 | Borough |
| Hickory | 89 | 389 | 415 | -1.52% | 10 | 38 | Township |
| Southview | 90 | 386 | 314 | 1.85% | 426 | 1 | CDP |
| Beallsville | 91 | 384 | 393 | -0.52% | 158 | 2 | Borough |
| Marianna | 92 | 384 | 396 | -0.52% | 196 | 2 | Borough |
| West Alexander | 93 | 374 | 412 | -3.86% | 306 | 1 | CDP |
| Finleyville | 94 | 367 | 376 | -0.54% | 2,198 | 0 | Borough |
| Joffre | 95 | 362 | 410 | -3.21% | 404 | 1 | CDP |
| Dunlevy | 96 | 360 | 369 | -0.55% | 677 | 1 | Borough |
| Bulger | 97 | 291 | 412 | -2.35% | 202 | 1 | CDP |
| Daisytown | 98 | 281 | 291 | -0.71% | 1,206 | 0 | Borough |
| Taylorstown | 99 | 273 | 260 | 1.11% | 259 | 1 | CDP |
| Fredericktown | 100 | 269 | 200 | -3.24% | 278 | 1 | CDP |
| Elco | 101 | 257 | 264 | -0.39% | 921 | 0 | Borough |
| Elrama | 102 | 233 | 470 | -2.1% | 1,596 | 0 | CDP |
| Millsboro | 103 | 221 | 503 | -11.95% | 280 | 1 | CDP |
| Twilight | 104 | 211 | 216 | -0.47% | 131 | 2 | Borough |
| Coal Center | 105 | 110 | 110 | 0% | 965 | 0 | Borough |
| West Middletown | 106 | 109 | 109 | 0% | 268 | 0 | Borough |
| Hendersonville | 107 | 108 | 145 | -11.48% | 271 | 0 | CDP |
| Meadowlands | 108 | 31 | 680 | -63.1% | 35 | 1 | CDP |
| Green Hills | 109 | 20 | 20 | 0% | 22 | 1 | Borough |
| Westland | 110 | 7 | 45 | -61.11% | 42 | 0 | CDP |
Peters is the largest city in Washington County, with a population of 23,272.
Westland is the smallest city in Washington County, with a population of 7.
There are 110 cities in Washington County, Pennsylvania.