Chemical Entities of Biological Interest, also known as ChEBI,[1][2] is a chemical database and ontology of molecular entities focused on 'small' chemical compounds, that is part of the Open Biomedical Ontologies (OBO) effort at the European Bioinformatics Institute (EBI).

Molecules directly encoded by the genome, such as nucleic acids, proteins and peptides derived from proteins by proteolytic cleavage, are not as a rule included in ChEBI.

ChEBI uses nomenclature, symbolism and terminology endorsed by the International Union of Pure and Applied Chemistry (IUPAC) and nomenclature committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB).

In addition, each data item is fully traceable and explicitly referenced to the original source.

It is related in scope other databases such as ChEMBL, ChemSpider, DrugBank, MetaboLights and PubChem.