Founded in 1907, Washington County is one of 77 counties in the state of Oklahoma. Historically, Washington County was formed from Cooweescoowee District of Cherokee Nation.. The city of Bartlesville is the county seat. With FIPS code of 147, Washington County has a population of 52,772 and area of 417 square miles (1,080 km2).
List of all cities in Washington County, OK alphabetically
| City/Town | Postal Code | Area Code |
| Bartlesville, OK | 74003 | 918 |
| 74004 | 918 | |
| 74005 | 918 | |
| 74006 | 918 | |
| Copan, OK | 74022 | 918 |
| Dewey, OK | 74029 | 918 |
| Eastside, OK | 74006 | 918 |
| Glenoak, OK | 74003 | 918 |
| Hog Shooter, OK | 74003 | 918 |
| Ochelata, OK | 74051 | 918 |
| Okesa, OK | 74003 | 918 |
| Phillips Petroleum, OK | 74004 | 918 |
| Ramona, OK | 74061 | 918 |
| Vera, OK | 74082 | 918 |