Abstract: The importance of the issue under consideration is determined by the increase of the role of the energy factor in the international policy. Along with traditional actors (states), large national and transnational oil and gas companies and various international institutions aimed at regulating international relations in the energy sphere have become the significant actors on the international scene in the energy sphere. An important stage of reforming the common energy policy of the EU was the 2015 Energy Union Strategy. The object of this research is the current energy policy of the EU. The research subject is its key actors - the European Commission, Gazprom, the EU and Russia. Using the historical, logical, comparative and analytical research methods the author attempts to answer the question “How is the interaction of the key actors of international relations in the energy sphere characterized after the formation of the European Energy Union?”. The author concludes that having vested the European Commission with extra authorities in the sphere of common energy, the EU turned it into a strong independent non-governmental actor of the global policy and bilateral international relations in the energy sphere. Interacting with the EU member-states, Russia’s authorities and the executives of the Gazprom company, the EC increases its leverage among the EU’s institutions and strengthens its role as a mediator on the international scene. The energy strategy has transformed interrelations between the EU and Russia from strategic partnership to traditional cooperation. However, Gazprom has maintained its role in the EU’s market using progressive rise of gas supply. The scientific novelty of the research consists in the definition of the current interaction between the actors of the international relations in the energy sphere.