| Zip Code | City | Population ↓ |
|---|---|---|
| 97603 | Klamath Falls | 32,376 |
| 97601 | Klamath Falls | 22,302 |
| 97624 | Chiloquin | 3,643 |
| 97623 | Bonanza | 2,705 |
| 97632 | Malin | 1,608 |
| 97633 | Merrill | 1,526 |
| 97627 | Keno | 654 |
| 97737 | Gilchrist | 492 |
| 97733 | Crescent | 468 |
| 97634 | Midland | 445 |
| 97731 | Chemult | 273 |
| 97621 | Beatty | 239 |
| 97626 | Fort Klamath | 223 |
| 97622 | Bly | 223 |
| 97625 | Dairy | 124 |
| 97639 | Sprague River | 33 |
| 97604 | Crater Lake | 0 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 17 ZCTAs in Klamath County, Oregon (US Census).