This chapter provides an overview of tourism ontology and how it can be used for developing e-tourism applications. The Semantic Web is the next generation Web; it uses background knowledge captured as an ontology and stored in machine-processable and interpretable form. Ontologies form the core of the Semantic Web and can be used to develop intelligent applications. However, generating applications based on ontology still remains a challenging task. This chapter presents a framework that provides a systematic process for developing intelligent e-tourism applications by using a tourism ontology.