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.