This COVID-19 Ontology is a data model for publishing COVID-19 data on the Web as a Knowledge Graph. The primary focuses of the model are (1) COVID-19 cases: the data for COVID-19 cases (e.g., active, recovered, deceased, migrated) on daily basis across the geo-location (district, state (province), and country), available resources and requirements; (2) COVID-19 patient data: nationality, symptom, suspected level of COVID -19, treatment facility, COVID-19 clinical facility, patient's travel history, inter-personal relationships between patients, suspected transmission reason, tracking of patient test results, etc.