| Zip Code | City | Population ↓ |
|---|---|---|
| 66067 | Ottawa | 15,904 |
| 66092 | Wellsville | 4,298 |
| 66076 | Pomona | 2,346 |
| 66095 | Williamsburg | 1,105 |
| 66080 | Richmond | 961 |
| 66078 | Princeton | 812 |
| 66079 | Rantoul | 626 |
| 66042 | Lane | 622 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 8 ZCTAs in Franklin County, Kansas (US Census).