This chapter explores the history of the development of human representations of a special immaterial realm located in the world around us—a realm in which, like in physical reality, every individual exists. This realm, which the author refers to as objective mental reality, is represented by similar mental constructs that are present in human consciousness. This chapter examines key concepts developed by researchers that correspond with objective mental reality, such as the world of ideas, collective and social consciousness, the symbolic universe, the third world, collective representations, intersubjectivity, and collective intelligence, among others. This chapter analyzes the mechanisms of institutionalization, legitimation, and internalization that ensure the integration of shared mental content into the structure of individual consciousness. Despite a long history of discussion, this realm remains poorly defined and not well understood; it has not been fully developed either theoretically or methodologically, and it has not yet been phenomenologically represented within contemporary psychology. The author argues for the need for a systematic, interdisciplinary investigation of objective mental reality as a distinct layer of reality. In the context of the world’s digital transformation, the spread of network-based forms of cooperation, and the growing role of intelligent systems, the study of objective mental reality is becoming critically important. The extent to which it is theoretically developed will determine our ability to scientifically understand, monitor, and manage collective mental processes that influence the dynamics of culture, social institutions, and mass behavior.