This book constitutes the refereed proceedings of the 27th IFIP WG 6.1 International Conference on Coordination Models and Languages, COORDINATION 2025, held in Lille, France, during June 17–19, 2025, as part of the 20th International Federated Conference on Distributed Computing Techniques, DisCoTec 2025. The 12 full papers and two invited contributions included in this book were carefully reviewed and selected from 29 submissions. This conference provides a well-established forum for the community of researchers interested in models, languages, architectures, and implementation techniques for coordination.