The dispute pitting Qatar against three of its Gulf neighbors led by Saudi Arabia is predominantly viewed as a consequence of Doha’s regional action, notably engaging with Iran, military ties with Turkey, and supporting Islamist groups across the region. In this interjection, we argue that the Saudi-Qatari tensions emerge out of competing understandings of authority and legitimacy, and with it, concern at the contestation of these claims. In other words, friction between Doha and Riyadh lies in conflicting perspectives held by Qatar and Saudi Arabia about the role of political Islam within the fabric of both states and their actions regionally. Fundamentally, the rivalry stems from contrasting relations between political and religious elites in each country which has taken on an increasing ‘political’ importance in tensions between Riyadh and Doha. Central to much of this are questions about the role played by the Muslim Brotherhood (and its various affiliates).