Founded in 1905, Benton County is one of 39 counties in the state of Washington. Historically, Benton County was formed from Yakima and Klickitat Counties. The city of Prosser is the county seat. With FIPS code of 5, Benton County has a population of 206,873 and area of 1,700 square miles (4,403 km2).
List of all cities in Benton County, WA alphabetically
| City/Town | Postal Code | Area Code |
| Benton City, WA | 99320 | 509 |
| Finley, WA | 99336 | 509 |
| Hanford Works, WA | 99352 | 509 |
| Kenn, WA | 99336 | 509 |
| Kennewick, WA | 99336 | 509 |
| 99337 | 509 | |
| 99338 | 509 | |
| Kiona, WA | 99320 | 509 |
| North Prosser, WA | 99350 | 509 |
| Paterson, WA | 99345 | 509 |
| Plymouth, WA | 99346 | 509 |
| Prosser, WA | 99350 | 509 |
| Richland, WA | 99352 | 509 |
| 99353 | 509 | |
| 99354 | 509 | |
| West Richland, WA | 99352 | 509 |
| 99353 | 509 |