In this paper, we present an ontology in OWL for Legal Case-based Reasoning. We outline some of the main motivations for providing an ontology in OWL, then discuss Legal Case-based Reasoning along the lines of CATO and given a method in which the factors of cases are compared and partitioned. An ontology in OWL, developed in the Protege ontology editor, is presented. The ontology is useful as a formal conceptualisation of what one reasons with in Legal Case-based Reasoning. We claim that as legal cases are the input to Legal Case-based Reasoning, the form in which cases are modelled ought to conditioned by the purpose to which they are put. Keywords. OWL, Ontology, Legal reasoning, Legal cases, Case-based reasoning