Introduction. The article describes the process of transformation of state-confessional relations in the Belarusian lands as part of the Russian Empire from the end of the 19th century to 1917. Methods and materials. To obtain verified results, the study is based on the analysis of administrative and regulatory materials, office documents of the Mogilev diocese, and domestic and foreign historiography. The study was conducted using an interdisciplinary methodology: historical-typological and historical-comparative methods, formal-legal, and the method of interpretation of legal norms were used. In addition, to identify the features of the socio-political discourse on the issue of changes in state-church relations, discourse analysis was used. Analysis. The historically established model of a religious state with the dominance of the Orthodox Church in the Russian Empire was established in the 19th century on Belarusian lands with a different confessional structure and traditions of state-church relations. The author noted a tendency to transition from the model of a religious state to the model of a secular state – in the period March – October 1917, the Provisional Government tried to establish an identification model of a secular state. This model corresponded to the religious system of Belarusian society with the dominance of the Orthodox Church and the expectations of socio-political actors and also ensured the implementation of religious rights and freedoms of adherents of other religions but was not fully implemented due to the transfer of power to the Bolshevik Party in October 1917. Results. Transformational processes in state-confessional relations in the Belarusian provinces took place in the direction from the model of a religious state to the model of a secular state as accompanying changes in the political system of the Russian Empire. Internal factors in the development of the state-confessional system of the Russian Empire, as well as the peculiarities of the confessional environment of the Belarusian provinces (diversification of the religious structure of Belarusian society, limitation of the rights of traditional actors rooted in the Belarusian religious environment, confessional dualism “Orthodoxy-Catholicism”), did not play a significant role in the transformation processes.