This is the Semantic Reasoning Evaluation Challenge (SemREC) Dataset. The details of the challenge are available at https://semrec.github.io/. These ontologies have been generated using OWL2Bench [1]. All the files are in RDF/XML format. The files are intended purely for use in reasoner benchmarking activities. The open-access extends only to this purpose. If required, users can generate more ontologies using OWL2Bench. Users can find the details about the benchmark and its usage in the following GitHub repository - https://github.com/kracr/owl2bench. [1] Singh G., Bhatia S., Mutharaju R., OWL2Bench: A Benchmark for OWL 2 Reasoners. ISWC 2020. Lecture Notes in Computer Science, vol 12507. Springer, Cham. https://doi.org/10.1007/978-3-030-62466-8_6