This book constitutes the refereed proceedings of the 46th IFIP WG 6.1 International Conference on Formal Techniques for Distributed Objects, Components, and Systems, FORTE 2026, held in Urbino, Italy, as part of the 21st International Federated Conference on Distributed Computing Techniques, DisCoTec 2026, during June 8–12, 2026.The 12 full papers, 1 short paper and 2 tool papers included in this book were carefully reviewed and selected from 27 submissions. They focus on fundamental research on theory, models, tools, and applications for distributed system.