56 zips
| Zip Code | City | Population ↓ |
|---|---|---|
| 15301 | Washington | 50,180 |
| 15317 | Canonsburg | 43,813 |
| 15057 | McDonald | 17,162 |
| 15063 | Monongahela | 10,479 |
| 15022 | Charleroi | 10,044 |
| 15367 | Venetia | 9,920 |
| 15332 | Finleyville | 8,206 |
| 15417 | Brownsville | 7,709 |
| 15021 | Burgettstown | 6,775 |
| 15330 | Eighty Four | 5,687 |
| 15342 | Houston | 5,110 |
| 15033 | Donora | 4,592 |
| 15323 | Claysville | 3,837 |
| 15312 | Avella | 3,631 |
| 15419 | California | 3,527 |
| 15314 | Bentleyville | 3,490 |
| 15067 | New Eagle | 2,207 |
| 15423 | Coal Center | 1,942 |
| 15321 | Cecil | 1,859 |
| 15333 | Fredericktown | 1,745 |
| 15360 | Scenery Hill | 1,541 |
| 15345 | Marianna | 1,540 |
| 15376 | West Alexander | 1,508 |
| 15329 | Prosperity | 1,438 |
| 15340 | Hickory | 1,303 |
| 15019 | Bulger | 1,236 |
| 15055 | Lawrence | 1,205 |
| 15358 | Richeyville | 1,141 |
| 15311 | Amity | 897 |
| 15427 | Daisytown | 856 |
| 15060 | Midway | 839 |
| 15331 | Ellsworth | 824 |
| 15477 | Roscoe | 794 |
| 15324 | Cokeburg | 749 |
| 15377 | West Finley | 737 |
| 15078 | Slovan | 611 |
| 15363 | Strabane | 569 |
| 15366 | Van Voorhis | 551 |
| 15054 | Langeloth | 527 |
| 15350 | Muse | 508 |
| 15429 | Denbo | 464 |
| 15313 | Beallsville | 398 |
| 15368 | Vestaburg | 367 |
| 15432 | Dunlevy | 343 |
| 15483 | Stockdale | 301 |
| 15004 | Atlasburg | 297 |
| 15347 | Meadow Lands | 285 |
| 15434 | Elco | 278 |
| 15038 | Elrama | 268 |
| 15412 | Allenport | 179 |
| 15365 | Taylorstown | 154 |
| 15053 | Joffre | 114 |
| 15361 | Southview | 92 |
| 15348 | Millsboro | 88 |
| 15379 | West Middletown | 61 |
| 15378 | Westland | 0 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 56 ZCTAs in Washington County, Pennsylvania (US Census).