The improvement of the efficacy of enterprise crowdsourcing activities is heavily dependent on finding, sharing, and integrating the right information for certain use cases. These efforts may include activities such as recommending a crowdsourcing task to a competent worker or evaluating an ongoing or completed crowdsourcing project. However, to pave the way for intelligent enterprise crowdsourcing platforms, the semantic richness of the data must be improved. Therefore, an ontology including a wide set of classes and properties is proposed in this paper. The ontology development is based on the ontology engineering methodology. A first general assessment of the ontology is given at the end of the paper, which describes how it addresses major crowdsourcing requirements.