Purpose: the modern post-classical stage of legal science development involves a general theoretical study of legality from the perspective of a sociological approach to law, which has not yet been fully implemented in works on the general theory of law. Legal positivism and normativism have largely exhausted their heuristic potential regarding legality, leading to a decline in scientific interest in it. In a theoretical context, it is necessary to consider legality as a complex social system that affects the functioning and development of the state and law in general. Methodology: dialectics and a systemic-structural approach. Results: in the structure of legality as a system, the author distinguishes between the endo-level (internal level) and the exo-level (external level). The basic characteristics and place of legality in the context of the sociological approach to law are outlined. The article substantiates the idea that legality is a methodological "reference point" that allows for the transition from the ought to the is in legal reality, and proposes an author's concept of legality in the focus of legal sociology. Scientific and practical significance: the article aims to update the understanding of legality from the perspective of society as a source of legal activity in general, and it addresses the epistemological gap by considering legality as a social system for the first time, opening up new horizons for the search for scientific truth regarding legality.