Founded in 1819, Washington Parish is one of 64 parishes in the state of Louisiana. Historically, Washington Parish was formed from part of St. Tammany Parish. The city of Franklinton is the parish seat. With FIPS code of 117, Washington Parish has a population of 45,133 and area of 676 square miles (1,751 km2).
List of all cities in Washington Parish, LA alphabetically
| City/Town | Postal Code | Area Code |
| Angie, LA | 70426 | 985 |
| Angie, LA | 70467 | 985 |
| Bogalusa, LA | 70427 | 985 |
| Bogalusa, LA | 70429 | 985 |
| Franklinton, LA | 70438 | 985 |
| Lees Creek, LA | 70427 | 985 |
| Mitch, LA | 70427 | 985 |
| Mitchell City, LA | 70427 | 985 |
| Mount Hermon, LA | 70450 | 985 |
| Plainview, LA | 70427 | 985 |
| Rio, LA | 70427 | 985 |
| Sheridan, LA | 70438 | 985 |
| Thomas, LA | 70438 | 985 |
| Varnado, LA | 70467 | 985 |