This paper explores the variation of citizenship in eight regional organisations (ROs). Since the 1980s, ROs have increasingly served as spaces for developing, regulating, and providing citizenship. However, current literature primarily takes a rights-based approach and focuses on a narrow set of cases without providing an account for the variation of citizenship in ROs. This paper offers a broad, conceptual approach to the study of regional citizenship and deploys a three-tiered conceptual framework consisting of rights, access, and belonging, to analyse how citizenship varies across different ROs. It challenges the current theorisation of regional citizenship, which is primarily rooted in the study of the EU’s rights-based approach. The analysis contributes to citizenship studies and comparative regionalism. It shows how citizenship varies across ROs, thus providing the first comprehensive cross-regional comparison. The empirical findings lead to the following insights. First, citizenship in regional organisations can be conceptualised as constitutional or practice-based. Second, there are different pathways to regional citizenship where practices might precede law or where citizenship in ROs remains a practice-based concept. Third, there is variation in the link between national and regional citizenship and how ROs provide access to regional citizenship.