56 ZIP Codes
| Zip Code | City | Population ↓ |
|---|---|---|
| 15301 | Washington | 50,348 |
| 15317 | Canonsburg | 43,871 |
| 15057 | McDonald | 16,583 |
| 15063 | Monongahela | 10,525 |
| 15022 | Charleroi | 9,959 |
| 15367 | Venetia | 9,906 |
| 15332 | Finleyville | 7,678 |
| 15417 | Brownsville | 7,363 |
| 15021 | Burgettstown | 7,110 |
| 15330 | Eighty Four | 6,023 |
| 15342 | Houston | 5,097 |
| 15033 | Donora | 4,572 |
| 15323 | Claysville | 3,860 |
| 15312 | Avella | 3,603 |
| 15314 | Bentleyville | 3,545 |
| 15419 | California | 3,421 |
| 15067 | New Eagle | 2,142 |
| 15321 | Cecil | 2,025 |
| 15333 | Fredericktown | 1,883 |
| 15423 | Coal Center | 1,846 |
| 15360 | Scenery Hill | 1,690 |
| 15345 | Marianna | 1,547 |
| 15340 | Hickory | 1,524 |
| 15376 | West Alexander | 1,441 |
| 15055 | Lawrence | 1,403 |
| 15329 | Prosperity | 1,390 |
| 15019 | Bulger | 1,056 |
| 15358 | Richeyville | 1,025 |
| 15331 | Ellsworth | 891 |
| 15060 | Midway | 853 |
| 15311 | Amity | 843 |
| 15427 | Daisytown | 789 |
| 15477 | Roscoe | 733 |
| 15078 | Slovan | 714 |
| 15324 | Cokeburg | 662 |
| 15377 | West Finley | 614 |
| 15363 | Strabane | 605 |
| 15429 | Denbo | 551 |
| 15366 | Van Voorhis | 550 |
| 15313 | Beallsville | 422 |
| 15350 | Muse | 373 |
| 15368 | Vestaburg | 353 |
| 15054 | Langeloth | 352 |
| 15347 | Meadow Lands | 350 |
| 15432 | Dunlevy | 326 |
| 15483 | Stockdale | 291 |
| 15434 | Elco | 280 |
| 15038 | Elrama | 279 |
| 15004 | Atlasburg | 217 |
| 15412 | Allenport | 208 |
| 15365 | Taylorstown | 145 |
| 15053 | Joffre | 127 |
| 15361 | Southview | 107 |
| 15379 | West Middletown | 64 |
| 15348 | Millsboro | 39 |
| 15378 | Westland | 0 |
The data shown reflect ZCTAs from the US Census. As of 2025, there are 56 ZCTAs in Washington County, Pennsylvania (US Census).