ChemFOnt is a chemical functional ontology resource developed by the Wishart Research Group to standardize how chemical functions and actions are described across biochemistry, food chemistry, and environmental chemistry. Its hierarchical, OWL-compatible framework organizes information about more than 341,000 biologically important chemicals into functional categories and structure-based chemical classes. The resource is available through a freely accessible web database and as a downloadable OWL file, allowing researchers to browse chemicals and ontology terms, perform structure and text searches, and integrate ChemFOnt into chemical databases or analytical software.

ChemFOnt connects chemicals with functional annotations and protein relationships, supporting applications such as metabolite set enrichment, data annotation, and discovery of connections among compounds. Its classifications draw on existing ontologies, published definitions, and curated chemical databases, with editorial oversight and standard procedures guiding updates. The project aims to support broader use across chemistry and related fields, including metabolomics, exposomics, metagenomics, genomics, and proteomics. ChemFOnt is designed to expand over time as its coverage and annotations develop.