Public sector supply chains operate within complex regulatory environments characterized by overlapping mandates, multi-tier governance structures, and high accountability requirements. Regulatory failures within such systems rarely remain localized; instead, they propagate across organizational, contractual, and jurisdictional boundaries, amplifying operational, financial, and reputational risks. This review paper develops a conceptual systems model of regulatory risk propagation and control in public sector supply chain networks, synthesizing insights from regulatory governance, systems theory, risk management, and supply chain resilience literature. The paper examines how regulatory risks emerge, interact, and cascade across interconnected public supply chain actors, including procuring entities, regulators, contractors, and oversight institutions. Emphasis is placed on identifying structural transmission pathways such as compliance dependencies, information asymmetries, enforcement latency, and policy misalignment that enable risk diffusion. The review further evaluates existing regulatory control mechanisms, including compliance audits, digital reporting systems, inter-agency coordination frameworks, and adaptive governance models, assessing their effectiveness in containing systemic risk. Building on these insights, the paper proposes an integrated conceptual framework that maps regulatory risk sources, propagation channels, feedback loops, and control levers across the public sector supply chain lifecycle. The model supports improved regulatory foresight, early warning capabilities, and coordinated risk mitigation strategies. By consolidating fragmented research into a unified systems perspective, this study contributes a structured foundation for policymakers, regulators, and public managers seeking to strengthen regulatory compliance, enhance transparency, and improve resilience in public sector supply chain networks (Oyeleye et al., 2024).