The dissertation study is devoted to the problems of the emergence and settlement of South-Eastern Ukraine by Old Believers in the 18th - early 20th centuries. The process of formation of Old Believer communities in the newly annexed territories of the Russian Empire was considered, and the economic, cultural, and spiritual life of Old Believers was analyzed. The study consists of an introduction, four chapters, conclusions, a list of used sources and literature. The introduction substantiates the relevance, scientific novelty, defines the object, subject and purpose of the dissertation; formulated main tasks; the practical significance of the obtained results is indicated. Chronological boundaries cover the period of the last quarter of the 18th - the beginning of the 20th century. The lower chronological limit of the work is the last quarter of the 18th century. It was after the signing of the Kyuchuk-Kainardzhii and Iasi peace treaties that the territory of South-Eastern Ukraine was included in the Russian Empire, which served as the beginning of the Old Believer colonization of the region. The upper limit is the fact that 1917 became a turning point for the Russian Empire and Ukraine in particular. The course of the Provisional Government in relation to religions and the church differed from the policy of the empire, which ceased to exist. The new government declared religious freedoms for citizens and religious organizations. From that time, a qualitatively different stage in the history of Old Believers began. The geographical boundaries of the study cover the territory of Southeast Ukraine. It corresponds to the territories of the modern Dnipropetrovsk, Donetsk, Zaporizhzhya, Luhansk, Mykolaiv, Odesa, Kherson regions and the Crimean Peninsula. The work is based on the principles of historicism, systematicity, integrity, objectivity, comprehensiveness. Applied general scientific, special-historical and interdisciplinary research methods. The combined application of these research rules contributed to the comprehensive analysis of the phenomenon of Old Believers in the territory of South-Eastern Ukraine in the specified historical period. In four sections of the study, the process of settlement by Old Believers in the Southeast of Ukraine is comprehensively analyzed, the characteristics of their faith, the formation of traditions, family structure, lifestyle, everyday life and economy are given. The first chapter, divided into three subsections, is devoted to clarifying the state of scientific development of the topic in historiography and the informative potential of the sources, as well as the theoretical and methodological foundations of the dissertation. The second section, which consists of two subsections, is devoted to the reasons for the church split in the 17th century. and religious foundations of the Old Believers. The prerequisites for the appearance and settlement of Old Believer communities in the territory of South-Eastern Ukraine are also considered. The third chapter, divided into two subsections, highlights the evolution of the legal position of Old Believers with power structures and the peculiarities of their relationship with the official church through the institutions of monotheism and missionary work. The fourth section, consisting of three subsections, is devoted to the peculiarities of the economic, social, spiritual and cultural life of Old Believer communities in the last quarter of the 18th - at the beginning of the 20th century. and the main manifestations of mutual relations between Old Believers at the family-marital, economic-household levels are traced. The relevance of the study of the phenomenon of Old Believers is due to the growing attention of researchers on this topic both in Ukraine and in the homeland of this phenomenon - in Russia. However, there are certain differences in the focus of historical research. The issue of the church split and the appearance of the Old Believers in the 17th century. were considered quite ambiguously, both three hundred and four hundred years ago, and in modern society. Its uniqueness lies not only in the protection of the ancient Russian Orthodox tradition, but also in the establishment of new development trends, evolutionary elevation. This is evidenced by the state and number of modern Old Believer communities in Ukraine. The scientific novelty of the obtained results is due primarily to the purpose and tasks of the work. For the first time, the characteristics of children's upbringing and the influence of the religious component on the future life of young people were highlighted for the Old Believers; a number of unpublished sources were introduced into scientific circulation, which made it possible to reveal the peculiarities of the daily life of the Old Believers; the role and quality of education in Old Believer communities was revealed, the level of teacher training, the availability of old books for teaching children...