The relevance of the research. Professionalism of intending officers manifests itself in such a quality as the ability to adapt to rapidly changing new circumstances, to changing conditions and the requirements associated with military service. The importance of educational support for the adaptation of cadets in a military university is determined by the necessity to improve the quality of professional training of intending officers of the Armed Forces of the Russian Federation so that they can effectively solve tasks related to their professional duties and combat service. The research purpose includes generalizing and demonstrating a variety of approaches to the definition of the concept “adaptation of cadets”; outlining the trend towards its interpretation in the context of specifics interaction between a cadet and a military, professionally-oriented, real educational space of a military university; determining the stages of cadets’ adaptation and the content of educational support for their adaptation in the specified institution. Methods: the analytical method was used to study the literature on the research issue; the theoretical synthesis was used to generalize and demonstrate the approaches to the concept “adaptation of cadets” and to explain the variety of its interpretations by scientists; the descriptive method was used to fix the stages and content of educational support. Results. The study shows the essence, features, components and problems of cadets’ adaptation to the conditions of a military university. It also proposes the stages (diagnostic, transformative) and the content of educational support for the adaptation of cadets in a military university. Appropriate methods, techniques, and questionnaires are recommended for implementation in practice to conduct successful diagnostic procedures at the first stage. At the second, transformative stage, it is proposed to carry out the educational support for the cadets’ adaptation taking into account the selected components of the adaptation process: psychophysiological, socio-psychological, educational-professional, service-functional and cultural-routine ones. Main conclusions: the study proposes the content of the phased educational support in the initial period of cadets’ mastering the educational and professional activities in order to meet the requirements for the quality of professional training of future officers of the Armed Forces of the Russian Federation. The practical significance of the research results is determined by the possibility of using them in the educational activities of a military university.