11 zips
| Zip Code | City | Population ↓ |
|---|---|---|
| 66968 | Washington | 1,454 |
| 66945 | Hanover | 1,063 |
| 66937 | Clifton | 691 |
| 66953 | Linn | 628 |
| 66943 | Greenleaf | 568 |
| 66933 | Barnes | 345 |
| 66944 | Haddam | 304 |
| 66962 | Palmer | 302 |
| 66958 | Morrowville | 198 |
| 66946 | Hollenberg | 161 |
| 66955 | Mahaska | 47 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 11 ZCTAs in Washington County, Kansas (US Census).