This book constitutes the thoroughly refereed post-workshop proceedings of the 20th International Conference on Web Engineering, ICWE 2020, held in Helsinki, Finland, in June 2020.*The 4 revised full 4 revised short papers were selected from 10 submissions. The workshops complement the main conference and explore new trends on core topics of Web engineering and provide an open discussion space combining solid theory work with practical on-the-field experience. The workshop committee accepted three workshops for publication in this volume: 1st International Workshop on the Web of Things for Humans (WoT4H 2020), 2nd Semantics and the Web for Transport workshop (Sem4Tra 2020), and 6th International Workshop on Knowledge Discovery on the Web (KDWEB 2020). *The conference was held virtually due to the COVID-19 pandemic.