A An ideal institutional framework is one of the fundamental prerequisites for establishing a financial sector supervisory system capable of maintaining financial stability, institutional integrity, and public confidence in the financial system. this study examines the institutional design of indonesia’s financial services authority (otoritas jasa keuangan/ojk) and the monetary authority of singapore (mas) from the perspective of comparative constitutional law. the research aims to identify the similarities and differences between the two institutions and to determine the most appropriate institutional design for indonesia’s financial services authority in carrying out its regulatory and supervisory functions within the financial services sector. this study employs normative legal research using statutory and comparative law approaches. the data consist of primary and secondary legal materials, which are analyzed qualitatively. the findings indicate that both the financial services authority and the monetary authority of singapore share the common objective of maintaining financial system stability and protecting the public interest. however, they differ in their institutional structures. the financial services authority operates as an independent supervisory body separate from the central bank, whereas the monetary authority of singapore integrates the functions of the central bank and financial services supervision within a single institution. the monetary authority of singapore’s institutional model is considered more effective in terms of policy coordination and supervisory efficiency, while indonesia’s financial services authority continues to face challenges in inter-institutional coordination. therefore, strengthening institutional independence, accountability, and coordination is essential to achieving a more effective and ideal financial services supervisory system in indonesia.