Relevance. Issues of discussion of international and national law have acquired particular relevance in the light of constitutional changes, occurred in 2020 in the Russian Federation. The primacy of national law, enshrined at the level of the Constitution of the Russian Federation, has significantly changed the interaction between the national and international legal order. At the same time, the sphere of freedom of conscience (religion) is one of the most important areas of legal regulation, which has both national and international legal aspects, which determines the relevance of the chosen research goal. The Purpose of the study is to analyze international legal and domestic regulation in the sphere of ensuring the right to freedom of conscience (religion), as well as to identify and resolve urgent problems of interaction of systemic law in the context of the right to freedom of conscience. The research objectives are: 1) determination of the place of the right to freedom of conscience (religion) in the system of international and national legal regulation, in particular, analysis of the concepts of “absolute law”, “jus cogens”, “general international law”; 2) consideration of the issue of the boundaries of freedom of religion in the understanding of the national law of the Russian Federation and international law. As a result of the accomplishment of the task, it is proposed to identify the main differences in this issue between the domestic and international legal order, as well as to put forward proposals to eliminate this discrepancy. Methodology. The key tool was the method of comparative analysis, as well as system analysis. In the course of the study, the main acts of the current legislation of the Russian Federation in the field, the most important international legal acts, the works of prominent specialists in international and constitutional rights were analyzed, a study of law enforcement acts (the practice of the courts of the Russian Federation, the European Court of Human Rights) was carried out. Conclusions. As a result, original conclusions were obtained regarding the need for the doctrinal inclusion of norms on freedom of conscience (religion) in the system of international common law. The conclusion is made about the need for a more complete consideration of the position of international judicial bodies in the legislative movement of the boundaries of the right to freedom of conscience (religion).