The study aims to present the periodization of the sociocultural genesis of private school education in Russia as an integrated process, combining historical and modern periods. The article addresses the comprehensive sociocultural study of the processes of historical genesis and modern development of the Russian non-state school as a pedagogical phenomenon to propose the periodization of its evolution. The scientific novelty lies in: the systematization of the historical and modern processes of private school education development, presented in the form of periodization, with the key sociocultural factor of influence, taken as its criterion; creating a holistic representation of the Russian private school genesis by combining in the proposed periodization all the sociocultural stages of its formation and development, starting from its inception in the 11th century and including the current period of its development; identifying the pedagogical specifics of the modern period of private schools development based on a theoretical analysis of the latest scientific and pedagogical publications devoted to their educational activities; introducing new information into the scientific discourse of pedagogical research, reflecting the analytics and statistics of modern private school education. As a result of the study, according to the major factor of sociocultural influence specified in the research, five periods of historical and pedagogical development of the Russian private school were defined, with all the stages of its historical genesis and modern development covered. The author has concluded that the complex socio-cultural influence of the society and state is the major factor determining the private school evolution and its pedagogical specifics in the modern period.