This chapter is devoted to the analysis of the social domain of objective mental reality. The author identifies two key components of social reality: the mental and the physical. The former belongs to objective mental reality and is represented in the consciousness of members of society by stable verbal and sensory representations of social entities (institutions, roles, norms, values, etc.). The latter is part of the physical world and is represented by the actions of people motivated by belief in the existence of these entities. The author stresses that social objects are constituted by consciousness and embedded in language, acquiring the status of reality only when they are internalized by the majority of individuals and when they begin to regulate these individuals’ behavior. Social reality exists insofar as it is present in their consciousness and in objective mental reality, and insofar as people act as if these social entities truly exist in the physical reality surrounding them. Its stability is determined by the cognitive coherence between individual representations and their continual reinforcement through social interaction. The key mechanisms involved in the formation and stabilization of social reality are examined: internalization, externalization, objectivation, legitimation, and reification. Examples are provided to illustrate how mental constructions acquire institutional form and may even be reified. The chapter also addresses the difficulty of distinguishing between the concepts of the social and the cultural, which represent overlapping zones within objective mental reality.