INTRODUCTION. The relevance of the research topic is determined, firstly, by the increasing importance of energy diplomacy for solving modern problems arising in the field of international energy cooperation, and secondly, by the significance of studying the problems of energy diplomacy from the point of view of the science of international law. Despite the fact that energy diplomacy is being formed and realizing its potential in the international legal environment, it is not given adequate attention to its role in the legal literature, including in scientific works on international law, which, in turn, looks like a gap in international legal science. The purpose of the work is to substantiate the international legal concept of energy diplomacy, to identify its connection with the classical model of diplomacy and at the same time specific, to objectively identify the main directions of the relationship between energy diplomacy and international law.MATERIALS AND METHODS. When writing the work, scientific works related to the topic, international treaties and documents of international law, acts of national legislation of states are analyzed. General scientific and special methods of cognition, including comparative legal and formal legal, were used as a research method.RESEARCH RESULTS. Energy diplomacy is derived from the “classical” model of diplomacy. There are various interpretations of diplomacy, focusing on its various aspects and manifestations. The article substantiates the understanding of diplomacy as a means of implementing the state’s foreign policy through the activities of special entities (bodies of foreign relations) using non-military techniques and methods in accordance with international law. The evolution of diplomacy and the emergence of its new forms are traced, their specificity and international legal component are noted. Taking into account the specifics of energy, international energy cooperation, their legal support based on the potential of international and national law, the independent nature of energy diplomacy, its increasing role in modern conditions is substantiated. The specific features of energy diplomacy are identified and its concept is proposed, taking into account the international legal component. In modern conditions, full-fledged regulatory and institutional legal foundations of the EU’s foreign energy policy and energy diplomacy have not developed. It is noted that the legitimacy of unilateral restrictive measures applied in energy diplomacy by a number of states is indisputable from the point of view of international law. The main directions of the relationship between energy diplomacy and international law are outlined in detail, options for legitimizing the national interests of states in the energy sector based on the potential of international law are highlighted.DISCUSSION AND CONCLUSIONS. The main conclusions of the study are as follows. Firstly, energy diplomacy is a new functional area of diplomatic activity. It has a single essence with “classical” diplomacy (to serve as a means of implementing foreign policy, in accordance with international law) and, at the same time, is characterized by a number of features derived from the energy sector and energy law (a special focus on the implementation of the goals and objectives of the state's foreign energy policy, the participation of energy departments in it and the connection of energy companies, methods used in it). Secondly, energy diplomacy and international law in the process of their development and functioning are mutually linked and have a reciprocal influence. International law, firstly, defines the legal framework and forms of implementation of energy diplomacy (as well as diplomatic activity in general), and secondly, plays a decisive role in legitimizing the national interests of states in the field of foreign energy policy carried out through energy diplomacy. In turn, energy diplomacy, relying on the potential of international law, contributes to ensuring energy security (national and international) and, thereby, to maintaining the international energy order. In general, energy diplomacy influences the process of creation and operation of international law norms and contributes to the development of international law.