Founded in 1807, West Baton Rouge Parish is one of 64 parishes in the state of Louisiana. Historically, West Baton Rouge Parish was one of the original 19 parishes. Was named Baton Rouge Parish until 1812. The city of Port Allen is the parish seat. With FIPS code of 121, West Baton Rouge Parish has a population of 27,792 and area of 203 square miles (526 km2).
List of all cities in West Baton Rouge Parish, LA alphabetically
| City/Town | Postal Code | Area Code |
| Addis, LA | 70710 | 225 |
| Brusly, LA | 70719 | 225 |
| Bueche, LA | 70729 | 225 |
| Erwinville, LA | 70729 | 225 |
| Port Allen, LA | 70767 | 225 |