Can. 1118 §1. A marriage between Catholics or between a Catholic party and a non-Catholic baptized party is to be celebrated in a parish church. It can be celebrated in another church or oratory with the permission of the local ordinary or pastor.
§2. The local ordinary can permit a marriage to be celebrated in another suitable place.
Thus, according to §2, you would need permission from the "local ordinary" (bishop) to have a wedding somewhere other than in a Catholic church.
