This book constitutes the refereed proceedings of the 26th International Conference on Runtime Verification, RV 2026, held in Kingston, ON, Canada, during October 6–9, 2026.

The 9 regular papers, 5 short papers, 4 tool papers, 1 tutorial paper, 1 benchmark paper and 3 tool showcase papers included in this book were carefully reviewed and selected from 65 submissions. They focus on topics in Runtime Verification including online and offline monitoring of formal specifications, shielding intelligent systems, quantitative verdict domains, as well as related research into AI safety and out-of-distribution detection. Runtime verification techniques have gained increasing acceptance as means to achieve system correctness, reliability, and robustness; they provide an additional level of rigor and effectiveness compared to conventional testing and are generally more practical than exhaustive formal verification.