Founded in 1896, Greer County is one of 77 counties in the state of Oklahoma. Historically, Greer County was formed from Greer County, Texas. The city of Mangum is the county seat. With FIPS code of 55, Greer County has a population of 5,487 and area of 639 square miles (1,655 km2).
List of all cities in Greer County, OK alphabetically
| City/Town | Postal Code | Area Code |
| Granite, OK | 73547 | 580 |
| Mangum, OK | 73554 | 580 |
| Reed, OK | 73554 | 580 |
| Willow, OK | 73673 | 580 |