Abstract: This article is devoted to the study of certain issues of international and domestic sports legal relations, and, above all, to the analysis of the concepts of "constitutional citizenship" and "sports citizenship". The issues of naturalization of athletes, compensation for the costs of their upbringing by the federation that naturalized them are very complicated. In the modern world, the role of sport in public relations continues to increase, which entails the need for high-quality legal regulation of this sphere of public relations. The study of the issues identified by the authors and the formulation of proposals with practical application is of particular relevance and, especially, in the context of the complication of these legal relations by the legally ambiguous geopolitical processes taking place in the interstate system. Through the methods of analysis, synthesis and a systematic approach, the process of studying normative legal acts and legal doctrines takes place. The use of the comparison method makes possible to assess the prospects of applying doctrinal judgments regarding the further codification of international law in the field of sports. The main conclusions of the study are the following:
- currently there are significant gaps in the field of legal regulation of legal relations involving professional athletes;
- in the field of national and international legal regulation of sports citizenship issues, there is a certain connection, as well as differences in the concepts of "constitutional citizenship" and "sports citizenship";
- it is necessary to implement a new codification of the norms of general international law, a more complete involvement of the mechanism of regional law-making;
- a full and high-quality implementation of national rule-making activities in the field of sports legal relations, complicated by a foreign element, is required. The scientific novelty of the research consist in the fact that the authors of the article have made conceptual proposals that can be applied in real life during the implementation of the law enforcement process in the field of sports. Special emphasis was placed on the need to comply with the norms governing the issues of sports citizenship to modern realities, since mass migration in the world contributes to the growth of the number of people receiving new both constitutional and sports citizenship, which results in the events that we can observe in both the field of general state policy and in the field of professional sports.