This thesis investigates mass denunciations in authoritarian hybrid regimes, using Turkey as an in-depth case to theorize their emergence and operation in contemporary autocratization. It argues that in political systems where formal democratic institutions coexist with authoritarian practices, denunciations can be mobilized through politically engineered reporting systems embedded within a nominally democratic order and enabled by its norms, procedures, and rhetoric. The Turkish case shows how mass denunciations, often associated with totalitarian rule, can re-emerge as strategically reconfigured instruments of hybrid autocratization. This reconfiguration unfolded through Turkey’s crisis-driven authoritarian trajectory. Across successive crises, the regime constructed internal enemies and framed hidden affiliations, dissent, and disloyalty as threats to national survival, thereby intensifying political demand for denunciatory information. This demand was channelled and institutionalized through reporting mechanisms that enabled citizens to supply accusations, grievances, and intelligence via formally legal and participatory channels. To theorize this process, the thesis conceptualizes denunciations through a demand–supply dynamic (Kalyvas, 2006): political actors demand information, and citizens supply it. To capture the top-down and bottom-up forces underpinning the creation and endurance of mass denunciations, it adopts a multi-level research design. At the macro level, it analyses the political ideology and discourse that justify, promote, and normalize denunciation, using the Discourse-Historical Approach. At the meso level, it investigates the institutional arrangements that facilitate reporting, drawing on expert interviews with legal, bureaucratic, and trade-union actors, as well as analysis of laws, policy documents, and administrative procedures. At the micro level, it explores the lived experiences of individuals who use or are victimized by the system through semi-structured interviews. Across these levels, the thesis examines how repression, co-optation, and legitimation operate in practice, structuring discourse, shaping institutions, and guiding citizen engagement. The thesis argues that reporting mechanisms in authoritarian hybrid regimes function as instruments of governance by integrating the authoritarian pillars of repression, co-optation, and legitimation (Gerschewski, 2013) into a unified system of control that turns democraticlooking tools toward authoritarian ends. At the discursive level, denunciations are cultivated through enemy-making, collaboration narratives, and appeals to civic duty. At the institutional level, they are embedded in legal, judicial, bureaucratic, and administrative processes that produce repressive outcomes for dissenters while delivering responsiveness and problemsolving benefits to regime-aligned citizens. At the individual level, denunciations generate incentives for participation, turning accusation into a practice justified through responsibility, loyalty, grievance, or self-interest. In this way, denunciations consolidate when political demand meets societal supply, embedding participatory repression in everyday social relations. Citizens become not only subjects of surveillance but also active participants in its enforcement, reinforcing the regime’s reach and resilience from below.