Psychology of religion is a rapidly developing field of interdisciplinary research, which covers a wide range of phenomena from the formation of religious conceptual systems and specifically religious patterns of behavior to processes of religious socialization and indoctrination, phenomena of religious fundamentalism and extremism, etc. The advent of the psychology of religion as an independent discipline in the first quarter of the 20th century went through a complicated formation, with a search of its subject and its methodology. This article briefly highlights the main stages of development of psychology of religion, sets out the key ideas of leading scientists, and the current state of the discipline. The history of psychology of religion is a history of “ups and downs”, in which Western and Russian traditions were clearly different. In the West, the development was more gradual and almost without serious interruption, and the main emphasis was on empirical research, while the history of the discipline in Russia was subject to political upheavals, which led to the domination of theoretical and historical works of descriptive nature.