Marriages between adherents of different indigenous beliefs have become a contentious issue in Indonesia. This is primarily because the identity of these believers, as recorded on their National Identity Cards, is ambiguously labeled as "Belief in the One Almighty God," without distinguishing between the various indigenous beliefs. It's noteworthy that Indonesia recognizes a diverse range of indigenous beliefs, each with its unique marital customs. The legal validity of civil registration for marriages between different indigenous belief adherents is questionable. The introduction of the Supreme Court Circular Letter No. 2 of 2023, addressing the registration of marriages between individuals of different religions and beliefs, warrants a deeper examination. This study employs a normative juridical method, utilizing secondary data and adopting both a statute and conceptual approach. Fundamentally, while the state prohibits interfaith marriages, marriages between different indigenous belief adherents are still legitimized. This is due to the lack of differentiation between one indigenous belief and another. Consequently, the enforcement of the Supreme Court Circular Letter No. 2 of 2023 cannot be applied to marriages between adherents of different indigenous beliefs.