During the 18th century, Naples witnessed the proliferation of a substantial ecclesiastical legislation and a more invasive intervention of the State in religious matters: this in conjunction with the more general consolidation of a national law. The paper intends to examine, in the light of the legislative production and the specific collections of ecclesiastical law of this period, the emergence of a true national ecclesiastical law, that is a system of rules specific to the Neapolitan legal system, aimed not only at regulating the relations between the Kingdom of Naples and the Church of Rome, but also at directly influencing the religious life of its clergy and its subjects