Problem setting. The opportunity to move to another country to develop a research career has always attracted scientists. For an individual researcher, international mobility is a chance to improve their skills, work in world-renowned research centers and institutions, be involved in modern research projects, and achieve success in their scientific career. Temporary intellectual migration of scientists is also of great importance for global science, as it helps to eliminate the heterogeneity of the development of scientific fields in different countries and, to some extent, solves the problem of «brain drain» from countries with a lower level of research system. analysis of recent researches and publications. Franzoni, C., Scellato, G. and Stephan, P., Fernández-Zubieta, A., Lawson, C., and Geuna, A., Janger, J. and Nowotny, K., Giovanni Abramo, Ciriaco Andrea D’Angelo, Flavia Di Costa have studied the issues of research mobility. Ukrainian scholars have mainly studied the academic mobility of students of higher education institutions in the context of innovations in modern higher professional education. The works of Bondar H.O., Magdyuk O.V., Rogulska O.O., Padalka G., Silivanova I.A., Vasylenko O.V. can be distinguished. Considering this, there is a need to study the phenomenon of researcher mobility in Europe and Ukraine and to study the experience of the European Union member states in regulating researcher mobility. Purpose of the research is to analyze the phenomenon of research mobility in the European Union and Ukraine, to compare the types and forms of academic mobility, to identify the problems faced by researchers during intellectual migration. article’s main body. The author studies the history of academic mobility in the European Union, which is inextricably linked to the Bologna Process the European educational movement for the mutual recognition of European higher education documents and the creation of the Higher Education Area. It is noted that this movement began with the aim of ensuring freedom of mobility of participants in higher education, primarily students and academic staff of higher education institutions, but eventually included researchers, emphasizing the importance of academic mobility of this category of subjects of scientific activity. The article describes the legal regulation of researcher mobility in Ukraine and the European Union. In particular, the author notes the application and significance of the principle of academic mobility in the regulation of labor relations of researchers in the European Union. The author provides a comparative characterization of the types and forms of academic mobility in the European Union and Ukraine, and in the course of analyzing them the author concludes that there are both similar types and forms of researcher mobility in the European Union and Ukraine, and different ones. The article examines the problems faced by researchers participating in academic mobility programs. The main problems are lack of research funding and lack of vacancies (in the European Union), insufficient funding, language problems and brain drain (in Ukraine). conclusions and prospects for the development. Mobility of researchers in the European Union is a widespread phenomenon encouraged by the EU’s research and innovation policy, in particular, academic mobility is one of the priorities for the development of the European Research Area (ERA). The author notes that Ukraine has updated legislation regulating the academic mobility of Ukrainian scientists, but the phenomenon of research mobility requires state support, since the country has a problem of «brain drain» when scientists leave for the European Union or other developed countries in search of a better life and do not return