Founded in 1864, Grant County is one of 36 counties in the state of Oregon. Historically, Grant County was formed from parts of old Wasco and old Umatilla counties. The city of Canyon City is the county seat. With FIPS code of 23, Grant County has a population of 7,272 and area of 4,529 square miles (11,730 km2).
List of all cities in Grant County, OR alphabetically
| City/Town | Postal Code | Area Code |
| Bates, OR | 97817 | 541 |
| Canyon City, OR | 97820 | 541 |
| Dayville, OR | 97825 | 541 |
| Fox, OR | 97856 | 541 |
| John Day, OR | 97845 | 541 |
| Kimberly, OR | 97848 | 541 |
| Long Creek, OR | 97856 | 541 |
| Monument, OR | 97864 | 541 |
| Mount Vernon, OR | 97865 | 541 |
| Prairie City, OR | 97869 | 541 |
| Ritter, OR | 97856 | 541 |
| Seneca, OR | 97873 | 541 |