This paper proposes a comparative inquiry on the differences and similarities between two bodies of administrative law: the administrative law of the Roman Catholic Church — an institution that combines elements typical of legal-rational authorities with a number of charismatic and traditional features — and the administrative laws of those States and regulatory systems beyond the State that are mainly legal-rational in nature. The comparison between canon administrative law and the administrative laws of mainly legal-rational regimes is developed by considering four interconnected aspects: i) their processes of emergence and development; ii) their constitutive “materials”; iii) their position within the legal order; and iv) their overall explanatory paradigms. The inquiry reveals that canon administrative law is based on a complex combination of religious and state elements, that gives rise to an unstable regulatory framework in which several internal tensions are intertwined. On a more general level, the comparative inquiry sheds some light on the links between the features of administrative law and the types of power (legal-rational power, charismatic power and traditional power) that administrative law serves and regulates.