This chapter provides an introductory account of the core elements of a generic critical realist social ontology for economics. The focus on social ontology in critical realism puts forward a position based on causal powers inhering in entities (such as structures and agents), complex interactions between causal powers in terms of arising events, and a consequent account of systems as ‘open’. According to its proponents, this social ontology is implicit within heterodox economic positions but is antithetical to mainstream economics. This is because mainstream economics pursues theorizations and applications that reduce to closed systems and typically assume and/or explore event regularities, often based on uses of mathematical models that are expressed in a deductive form. Critical realism’s great strength is that it provides a more plausibly realistic account of the economy as an intrinsic aspect of society; in so doing it ‘under-labours’ for heterodox approaches. However, in so far as it only under-labours, critical realism can also be developed in a variety of ways based on different issues for methods and methodology.