Introduction. The article concentrates on the religious policy of the Russian Empire in the Early Modern Time. For the first time in historiography, a study was carried out concerning the place of Catholic missionaries who settled on the southern outskirts of Russia, in the religious policy of Russian secular and spiritual authorities. Materials and methods. The base of the study was the correspondence of the Collegium of Foreign Affairs with the Holy Synod, as well as other institutions and officials, characterizing the scale of the presence and direction of activity of Catholic orders on the territory of Russia. The methodology of the study has been determined by the structural and functional approach to the system of state bodies of Russia. In combination with this approach, a historical-genetic method was used, which is optimal for understanding the evolution of the structure of power in the Russian Empire from the time of Peter the Greatto the middle of the reign of Empress Elizaveta Petrovna. The results of the research are presented in the section “Catholic missionaries in the south of Russia by the middle of the 18th century: political and diplomatic aspects”. In it, the Capuchin Order is designated as the most active force of Catholic missionary work in the Russian south, which managed to prevail over others Catholic orders in dispute for influencing on the ethno-confessional groups of the studied region. It has been determined that the Capuchins in Russia gained constant diplomatic support from the Austrian monarchy. The activity of missionaries in Astrakhan and Nizhyn was traced, the place of the Armenian communities in the missionary plans of the Capuchins on the territory of Russia is shown. The influence on the position of the Capuchins of Russian-Austrian relations is emphasized, in particular of the “Austrian system” — the orientation of Russian diplomacy towards the Austrian court. The idea is carried out that the attitude of the Russian authorities in the capital and in the localities towards the Capuchins in such conditions was indifferent or patronizing, while in fact the Russian secular authorities did not take into account the violation of the prerogatives of the ruling Orthodox (Greek-Russian) church. In order of discussion (part “Missionaries in the Russian Borderlands: source study andhistoriographical observations” of the abovementioned section of the article), the main interpretations of Catholic missionaryism, found in the literature on Catholicism in Russia, have been identified. Conclusion. The author states that the reasons for the interest of Catholic missionaries to the southern Russian outskirts and their population were objective. The reaction of the Russian secular authorities to such an interest was little, and their awareness of the legal necessity of appropriate regulatory measures developed slowly.