<p>Several large databases in biology are now making their information available through the Resource Description Framework (RDF). RDF can be used for large datasets and provides a graph-based semantics. The Web Ontology Language (OWL), another Semantic Web standard, provides a more formal, model- theoretic semantics. While some approaches combine RDF and OWL, for example for querying, knowledge in RDF and OWL is often expressed differently. Here, we propose a method to generate OWL ontologies from SPARQL queries using n-ary relational patterns. Combined with background knowledge from ontologies, the generated OWL ontologies can be used for expressive queries and quality control of RDF data. We implement our method in a a prototype tool available at https://github.com/ bio- ontology- research- group/SPARQL2OWL.</p>