Social ontology is a branch of ontology. Ontology is the philosophical study of being and existence; social ontology, specifically, examines the social world, and the entities that arise out of social interaction. A primary concern of social ontology is social groups, whether or not they exist (and if so, in what way), and if so, how they differ from any given collections of people. Much of social ontology is conducted within the social sciences, and is concerned with many of the same entities, such as institutions, socio-economic status, race, and language.

Notable contemporary philosophers who study social ontology include John Searle, Margaret Gilbert, Amie Thomasson, Tony Lawson and Ruth Millikan.

Lynne Rudder Baker considered the subject in her posthumously published paper, "Just What is Social Ontology?". In contrast to Searle, she concluded that social phenomena (those things which require the existence of a social community, for example "mind-dependent items like judicial systems, copyrights, and corporations") are relevant to ontology, and that it was not necessary to reduce them to a physical definition.