This book constitutes the refereed proceedings of the 23rd IFIP WG 6.1 International Conference on Distributed Applications and Interoperable Systems, DAIS 2023, held in Lisbon, Portugal, during June 19-23, 2023, as part of the 18th International Federated Conference on Distributed Computing Techniques, DisCoTec 2023. The 7 full papers presented in this book were carefully reviewed and selected from 13 submissions. The papers cover the following topics: distributed algorithms and systems; data management; and distributed architectures.