Religious identity politics has become a key dynamic in Indonesia’s post-Reform democracy. This study analyses this phenomenon through the lens of the Global South, integrating the concepts of democratisation, populism, digital media, religion–state relations, and postcolonial legacies. The research employs a qualitative approach, utilising an interpretative-critical case study design through discourse analysis. The findings indicate that democratisation has not diminished the role of religion in politics. Rather, it has created a structure of opportunities that allows religious identity to be transformed into a source of political legitimacy, mobilisation, and contestation. The fragmentation of religious authority, the rise of digital religious populism, and the ongoing negotiation between nationalism and transnational religious currents within a postcolonial state reinforce this process. These findings suggest that the politics of religious identity cannot be understood as an episodic electoral phenomenon but rather as a political ecosystem shaped by the interaction among democratic institutions, colonial history, religious actors, digital technology, and global networks. This study expands the analysis of identity politics in the Global South’s democracies by offering a more relational and multidimensional interpretation, whilst emphasising that the quality of democracy is determined not by the presence or absence of religion in the public sphere, but by the ability of democratic institutions to manage identity competition inclusively and constitutionally.