Ontologies are crucial for the life sciences, where it’s necessary to categorize and organize the many different kinds of entities being studied, from the molecular level through to the organism and ecosystem level. The Common Ontology for Biology (COB) is an upper ontology intended for this purpose. It is designed to interoperate with other upper ontologies that are part of the Open Bio Ontologies (OBO) framework, including the Relation Ontology (RO) and the Basic Formal Ontology (BFO), providing domain-scientist friendly terms and intuitive groupings.