This book constitutes revised selected papers from the workshops held at the 26th International Conference on Parallel and Distributed Computing, Euro-Par 2020, which took place in Warsaw, Poland, in August 2020. The workshops were held virtually due to the coronavirus pandemic. The 27 full papers presented in this volume were carefully reviewed and selected from 50 submissions. Euro-Par is an annual, international conference in Europe, covering all aspects of parallel and distributed processing. These range from theory to practice, from small to the largest parallel and distributed systems and infrastructures, from fundamental computational problems to full-edged applications, from architecture, compiler, language and interface design and implementation to tools, support infrastructures, and application performance aspects.