Founded in 1882, Klamath County is one of 36 counties in the state of Oregon. Historically, Klamath County was formed from Western part of Lake County. The city of Klamath Falls is the county seat. With FIPS code of 35, Klamath County has a population of 70,164 and area of 5,945 square miles (15,397 km2).
List of all cities in Klamath County, OR alphabetically
| City/Town | Postal Code | Area Code |
| Beatty, OR | 97621 | 541 |
| Bly, OR | 97622 | 541 |
| Bonanza, OR | 97623 | 541 |
| Cascade Summit, OR | 97425 | 541 |
| Chemult, OR | 97731 | 541 |
| Chiloquin, OR | 97624 | 541 |
| 97639 | 541 | |
| Crater Lake, OR | 97604 | 541 |
| Crescent, OR | 97733 | 541 |
| Crescent Lake, OR | 97425 | 541 |
| 97733 | 541 | |
| Dairy, OR | 97625 | 541 |
| Diamond Lake, OR | 97731 | 541 |
| Fort Klamath, OR | 97626 | 541 |
| Gilchrist, OR | 97737 | 541 |
| Keno, OR | 97627 | 541 |
| Kingsley Field, OR | 97601 | 541 |
| Klamath Falls, OR | 97601 | 541 |
| 97602 | 541 | |
| 97603 | 541 | |
| 97625 | 541 | |
| Malin, OR | 97632 | 541 |
| Merrill, OR | 97633 | 541 |
| Midland, OR | 97634 | 541 |
| OreTech, OR | 97601 | 541 |
| Sprague River, OR | 97639 | 541 |
| Worden, OR | 97601 | 541 |