This book constitutes the refereed post proceedings of the 17th Research Conference on Metadata and Semantic Research, MTSR 2023, held in Milan, Italy, during October 25–27, 2023.   The 27 papers included in this book were carefully reviewed and selected from 75 submissions. These papers are compiled from the following eight tracks of the conference: Digital Libraries, Information Retrieval, Big, Linked, Social, and Open Data; Agriculture, Food, and Environment; Open Repositories, Research Information Systems, and Data Infrastructures; Digital Humanities and Digital Curation; Cultural Collections and Applications; European and National Projects; Knowledge IT Artifacts in Professional Communities and Aggregations; and Metadata, Identifiers, and Semantics in Decentralized Applications, Blockchains, and P2P Systems.