The main trend of research about religion and state in modern Saudi Arabia has focused on the role of the former as a basis of legitimization of the Saudi dynastic government. A number of studies have emphasized efforts of the Saudi regime in preserving the religious nature of the state as a basis for their rule. However, despite the analysis of the traditional role of the religious scholars (ulama) and the religious opinion (fatwa, pl. fatwa or fatwas), in underscoring this legitimization, these studies have not provided concrete models of the use of religion as a source of maintaining the legitimization of the regime's hegemony. In this article, I will attempt to present such a concrete model by discussing the traditional doctrine of siyâsa shariyya as a principal method in preserving the religious nature of the state.