Is it OK for Catholics to have their marriage witnessed by a priest of the Society of St. Pius X?

Answer

According to the Code of Canon Law, Catholic marriages ordinarily must be witnessed by the local ordinary or the parish priest, or by a minister—usually a priest or deacon—delegated by them to do so (canon 1108 §1). Because SSPX priests do not have faculties from the Church to witness Catholic marriages, Catholics may not have their marriage witnessed by an SSPX priest.