O Online gambling is rampant not only in indonesia but also in several countries, including singapore. however, regulations and sanctions differ between indonesia and singapore. the problem raised is the legal system of online gambling in indonesia and singapore, and the differences in online gambling regulations in indonesia and singapore. to answer the problem formulation, the author used a normative research method based on secondary data with a descriptive-analytical nature and deductive logic in drawing conclusions. the research concluded that the legal system for regulating online gambling in indonesia adheres to the civil law system, while singapore adheres to the common law system. online gambling regulations in indonesia adhere to a total prohibition through the criminal code and the ite law, while singapore regulates with a controlled approach through the remote gambling act 2014, which allows for limited exceptions. the differences in online gambling regulations are based on differences in the underlying legal principles. indonesia focuses on the principles of legal certainty, morality, and a total prohibition approach through the criminal code and the ite law. meanwhile, singapore emphasizes legal effectiveness, proportionality, and social risk control through its special regulation, the remote gambling act 2014. the research results show that indonesia, as a civil law country, adopts an approach based on a total prohibition in the criminal code and the ite law. in contrast, singapore, which is based on a common law system, adopts a regulatory-controlled approach through its special regulation on online gambling, the remote gambling act 2014.