§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.
§3. A marriage between a Catholic party and a non-baptized party can be celebrated in a church or in another suitable place.
Source: Code of Canon Law (Vatican.va)