The article deals with the main directions of cooperation in the sphere of education within the framework of the Union State. The novelty of the study lies in the fact that for the first time it formulates and introduces the authors’ research position, clearly outlines the boundaries separating the processes which take place within the Union State, and traces the development of the Russian-Belarusian interaction. In the context of this concept the authors identify and formulate the main stages of development of these processes and systematize the main trends of formation of the normative-legal base of the common educational space and measures for its practical implementation. They examine the interaction between the Russian Federation and the Republic of Belarus within the Union State framework in the general context of the Union State building. The following stages are outlined: the preliminary stage from 1995 through 1999 included the maintenance of equal rights of citizens at the level of interstate relations and in the beginning of the Union State building; the second stage from 1999 through 2012 provided the normative-legal base of the educational space of the Union State and implementation of the existing norms; the third stage from 2012 through 2018 was characterized by gradual growth of attention of the governing bodies of the Union State to the problems of humanitarian cooperation, adaptation of the normative-legal acts to the actual changes in the sphere of education of the two countries; the fourth stage from 2018 until now is regarded as a high time for formation of a single space of education of the Union State for further development of integration. The article categorizes and characterizes the actions taken by the bodies of the Union State, educational institutions and professional circles in order to develop cooperation in the field of education. The study identifies the role of diaspora public organizations in the processes under consideration. The authors conclude about the special role of educational and scientific organizations, professional associations and civil society institutions of the two countries in the development of a unified educational space.