While considerable revisions of rentier state theory have advanced this body of literature, the relationship between rentierism and religion remains under-theorised. Much existing scholarship focuses on the ability of regimes benefitting from hydrocarbon rents to co-opt potential political opponents and economic competition, largely ignoring their dominance of the religious sector. Indeed, rentier state theory presumes that government autonomy extends beyond economics into politics, and theorists like Hertog (2011) have rightly demonstrated the extent to which state autonomy has been overstated in the political economy sphere and in society more broadly. As he explains, the state puts limits on its own authority during the state-building period through its creation of clients, which require distributive obligations, even though they provide political support. While such obligations tend to be described as primarily affecting economic and political life, I argue that rentier states of the Arabian Peninsula also have significant distributional relationships with the religious sphere, which allow for general co-optation of this sphere yet also bind leaders in the Gulf to appear, at least to a certain extent, to adhere to basic tenets of Islam. Co-optation of the religious sector is by no means unique to the Gulf states, as bureaucratisation and the propagation of authoritarian structures across the Arab world enhanced state authority over religion over the course of the twentieth century. This situation allows states, in turn, to co-opt popular religious leaders as a means of enhancing their legitimacy within society and heading off potential grounds for protests from the religious sphere. I hope to discover what is unique about countries with distributive capabilities due to hydrocarbon wealth versus other types of authoritarian states when it comes to control of the religious sphere by examining existing literature linked to the rentier state, empirical observations about the role of state religious authorities in Gulf societies, and results of a survey conducted in December 2017 by YouGov measuring the influence of religious authorities in Gulf states. Certainly, rulers of the wealthier Gulf states are in a position to finance large mosques and religious schools within their own borders, in addition to funding religious education abroad. We hope to determine how effective religious co-optation is in reality, its political and social consequences, and what it means for rentier state theory.