In this article, we are consciously referring to the cardinal problem of public and private law. In the modern legal literature, there is practically no comprehensive development of the concept of a legal entity under public law. However, it is used by some researchers, and often in a variety of ways, being apparently sometimes a concept lacking in certain content, or it is used as an additional scientific argument in scientific research. In this regard, there is an obvious need to clarify the essence of the concept of a legal entity under public law. Moreover, the question first arises as to which of the legal sciences should the task of its development become: the science of civil (private) law, any of the scientific disciplines of public law or is it a category belonging to the general theory of law?