Critical social ontology is any study of social ontology that is done in order to critique ideology or end social injustice. The goal of this paper is to outline what I call the fundamentality approach to critical social ontology. On the fundamentality approach, social ontologists are in the business of distinguishing between appearances and (fundamental) reality. Social reality is often obscured by the acceptance of ideology, where an ideology is a distorted system of beliefs that leads people to promote or accept widespread social injustices. Social reality is also obscured in cases where ordinary thought and language simply is not perspicuous enough to represent the social objects, kinds, and structures that are central to understanding social injustice. In both cases, I argue that the critical social ontologist will benefit from using the tools and concepts of fundamental metaphysics.