72 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Peters township | 1 | 23,272 | 22,958 | 0.02% | 1,193 | 19.50 | Township |
| North Strabane township | 2 | 17,565 | 15,690 | 2.47% | 644 | 27.26 | Township |
| Washington township | 3 | 15,828 | 14,867 | 1.39% | 405 | 39.07 | Township |
| Cecil township | 4 | 15,337 | 14,651 | 0.9% | 582 | 26.36 | Township |
| Washington | 5 | 13,607 | 13,162 | 0.66% | 4,646 | 2.93 | City |
| Amity township | 6 | 13,469 | 13,392 | 0.19% | 745 | 18.08 | Township |
| Canonsburg | 7 | 9,549 | 9,748 | -0.42% | 4,134 | 2.31 | Borough |
| South Strabane township | 8 | 9,548 | 9,640 | -0.33% | 415 | 22.99 | Township |
| Chartiers township | 9 | 9,222 | 8,679 | 0.29% | 375 | 24.61 | Township |
| Lawrence township | 10 | 7,225 | 7,500 | -0.84% | 88 | 82.54 | Township |
| Washington township | 11 | 6,753 | 6,878 | -0.34% | 211 | 31.95 | Township |
| Washington township | 12 | 6,557 | 6,544 | -0.01% | 278 | 23.56 | Township |
| Union township | 13 | 5,526 | 5,384 | 1% | 361 | 15.29 | Township |
| Carroll township | 14 | 5,277 | 5,380 | -0.36% | 391 | 13.48 | Township |
| Washington township | 15 | 5,155 | 5,145 | 0.04% | 289 | 17.84 | Township |
| North Franklin township | 16 | 4,733 | 4,824 | -0.36% | 645 | 7.33 | Township |
| Washington township | 17 | 4,541 | 4,464 | 0.22% | 323 | 14.07 | Township |
| Donora | 18 | 4,459 | 4,561 | -0.45% | 2,348 | 1.90 | Borough |
| Washington township | 19 | 4,343 | 4,392 | -0.37% | 96 | 45.18 | Township |
| Smith township | 20 | 4,168 | 4,233 | -0.36% | 121 | 34.46 | Township |
| California | 21 | 4,157 | 5,361 | -5.48% | 378 | 11.01 | Borough |
| Charleroi | 22 | 4,133 | 4,235 | -0.48% | 5,424 | 0.76 | Borough |
| Monongahela | 23 | 4,047 | 4,147 | -0.49% | 2,116 | 1.91 | City |
| Fallowfield township | 24 | 4,004 | 4,100 | -0.42% | 188 | 21.27 | Township |
| Amwell township | 25 | 3,635 | 3,682 | -0.3% | 81 | 44.80 | Township |
| Washington township | 26 | 3,605 | 3,888 | -1.5% | 363 | 9.93 | Township |
| Washington township | 27 | 3,154 | 3,124 | 0.25% | 102 | 31.02 | Township |
| South Franklin township | 28 | 2,818 | 2,871 | -0.35% | 137 | 20.57 | Township |
| Washington township | 29 | 2,618 | 2,579 | 0.34% | 93 | 28.04 | Township |
| Bentleyville | 30 | 2,315 | 2,355 | -0.34% | 627 | 3.69 | Borough |
| Hickory township | 31 | 2,285 | 2,316 | -0.04% | 144 | 15.85 | Township |
| East Bethlehem township | 32 | 2,270 | 2,312 | -0.35% | 448 | 5.07 | Township |
| Washington township | 33 | 2,094 | 2,130 | -0.47% | 118 | 17.71 | Township |
| New Eagle | 34 | 2,002 | 2,057 | -0.55% | 1,970 | 1.02 | Borough |
| Buffalo township | 35 | 1,947 | 1,983 | -0.26% | 96 | 20.35 | Township |
| Washington township | 36 | 1,846 | 1,892 | -0.27% | 39 | 47.59 | Township |
| Washington township | 37 | 1,813 | 1,863 | -0.71% | 55 | 32.94 | Township |
| Washington township | 38 | 1,813 | 1,753 | 1.17% | 76 | 23.88 | Township |
| East Washington | 39 | 1,809 | 1,851 | -0.44% | 4,029 | 0.45 | Borough |
| Washington township | 40 | 1,728 | 1,768 | -0.46% | 36 | 48.22 | Township |
| Washington township | 41 | 1,650 | 1,648 | 0.18% | 43 | 38.14 | Township |
| Lawrence township | 42 | 1,591 | 1,611 | -0.31% | 46 | 34.46 | Township |
| North Bethlehem township | 43 | 1,521 | 1,551 | -0.39% | 69 | 22.08 | Township |
| West Pike Run township | 44 | 1,509 | 1,543 | -0.4% | 93 | 16.25 | Township |
| Independence township | 45 | 1,491 | 1,510 | -0.2% | 58 | 25.75 | Township |
| Monongahela township | 46 | 1,426 | 1,485 | -0.42% | 82 | 17.43 | Township |
| Burgettstown | 47 | 1,388 | 1,425 | -0.5% | 2,232 | 0.62 | Borough |
| Cross Creek township | 48 | 1,374 | 1,373 | 0.29% | 50 | 27.53 | Township |
| Washington township | 49 | 1,296 | 1,336 | -0.84% | 68 | 18.93 | Township |
| East Finley township | 50 | 1,280 | 1,288 | 0.16% | 36 | 35.11 | Township |
| North Charleroi | 51 | 1,268 | 1,302 | -0.55% | 4,934 | 0.26 | Borough |
| West Bethlehem township | 52 | 1,260 | 1,291 | -0.55% | 56 | 22.42 | Township |
| Washington township | 53 | 1,242 | 1,286 | -0.48% | 50 | 24.94 | Township |
| Houston | 54 | 1,140 | 1,169 | -0.52% | 2,774 | 0.41 | Borough |
| Ellsworth | 55 | 915 | 940 | -0.54% | 1,238 | 0.74 | Borough |
| Midway | 56 | 909 | 923 | -0.33% | 2,066 | 0.44 | Borough |
| Claysville | 57 | 712 | 729 | -0.42% | 2,304 | 0.31 | Borough |
| Roscoe | 58 | 699 | 719 | -0.57% | 3,841 | 0.18 | Borough |
| Cokeburg | 59 | 611 | 626 | -0.49% | 1,736 | 0.35 | Borough |
| Allenport | 60 | 473 | 485 | -0.42% | 222 | 2.13 | Borough |
| Stockdale | 61 | 414 | 424 | -0.48% | 1,605 | 0.26 | Borough |
| Long Branch | 62 | 410 | 420 | -0.48% | 129 | 3.19 | Borough |
| Beallsville | 63 | 384 | 393 | -0.52% | 158 | 2.43 | Borough |
| Marianna | 64 | 384 | 396 | -0.52% | 196 | 1.96 | Borough |
| Finleyville | 65 | 367 | 376 | -0.54% | 2,198 | 0.17 | Borough |
| Dunlevy | 66 | 360 | 369 | -0.55% | 677 | 0.53 | Borough |
| Daisytown | 67 | 281 | 291 | -0.71% | 1,206 | 0.23 | Borough |
| Elco | 68 | 257 | 264 | -0.39% | 921 | 0.28 | Borough |
| Twilight | 69 | 211 | 216 | -0.47% | 131 | 1.61 | Borough |
| Coal Center | 70 | 110 | 110 | 0% | 965 | 0.11 | Borough |
| West Middletown | 71 | 109 | 109 | 0% | 268 | 0.41 | Borough |
| Green Hills | 72 | 20 | 20 | 0% | 22 | 0.92 | Borough |
Peters township is the largest city in Washington County, with a population of 23,272.
Green Hills is the smallest city in Washington County.
There are 72 cities in Washington County, Pennsylvania.