The purpose of the article is to analyse the Muslim intellectual tradition in Indonesia in contexts of social problems of Islam and the Ummah. The novelty of the study for Russian historiography and Indonesian studies lies in the comprehensive analysis of the main trends and directions in the development of Muslim social thought in modern Indonesia. Methodologically, the article is based on the principles of intellectual and social history, which allow us to perceive and analyse the experience and academic contribution of Muslim intellectuals involved in discussing the social problems of Islam, through the prism of the production and reproduction of meanings as a process of invention of traditions. The article analyses the main features of the perception and analysis of the problems of radicalisation of Islam and its consistent fragmentation in modern Muslim thought in Indonesia. It is expected that Ummah intellectuals, analysing the social characteristics of Islam, as well as the threats of radicalization and the rise of Islamic fundamentalism that Indonesia as a secular state face, contribute to the development of the identity of modern Indonesian society. The article shows that 1) Muslim intellectuals pay special attention to the problems of radicalisation of Islam, 2) the study of regional characteristics of Islam plays a signifi cant role in the development of the sociology of Islam, 3) the radicalisation of Islam is perceived as a multi-level process associated with the growth of political contradictions and the deepening of social and regional trends fragmentation of society. The author’s main conclusions are: 1) Muslim intellectuals make a signifi cant contribution to the development and progress of modern Muslim sociology in Indonesia, 2) academic scientifi c journals play a leading role in the production and relaying of social knowledge and experience of the Ummah, 3) the modern Muslim intellectual tradition in Islamic sociology is based based on the principles of interdisciplinarity and moderately fragmented.