Founded in 1807, Assumption Parish is one of 64 parishes in the state of Louisiana. Historically, Assumption Parish was one of the original 19 parishes. The city of Napoleonville is the parish seat. With FIPS code of 7, Assumption Parish has a population of 20,689 and area of 364 square miles (943 km2).
List of all cities in Assumption Parish, LA alphabetically
| City/Town | Postal Code | Area Code |
| Belle Rose, LA | 70341 | 225 |
| Bruly Saint Martin, LA | 70341 | 225 |
| Labadieville, LA | 70372 | 985 |
| Magnolia, LA | 70341 | 225 |
| Napoleonville, LA | 70390 | 985 |
| Paincourtville, LA | 70391 | 985 |
| Pierre Part, LA | 70339 | 985 |
| Plattenville, LA | 70393 | 985 |