Post Offices List in Benton County, Washington:
| Benton City Post Office | 909 Dale Ave, Benton City, WA 99320 |
| Kennewick Post Office | 525 S Auburn St, Kennewick, WA 99336 |
| Paterson Post Office | 48801 W Prior Ave, Paterson, WA 99345 |
| Plymouth Post Office | 72304 Se 3rd Ave, Plymouth, WA 99346 |
| Prosser Post Office | 1103 Meade Ave, Prosser, WA 99350 |
| Richland Post Office | 639 Cullum Ave, Richland, WA 99352 |
| West Richland Post Office | 4801 W Van Giesen St, West Richland, WA 99353 |