This book constitutes the refereed proceedings of the 16th International Conference on Web Engineering, ICWE 2016, held in Lugano, Switzerland, in June 2016.The 19 full research papers, 13 short papers, 3 vision papers, 11 demonstrations, 5 posters, 6 PhD Symposium  and 4 tutorials presented were carefully reviewed and selected from 120 submissions. The 16th edition of ICWE accepted contributions related to different research areas revolving around Web engineering, including: Web application modelling and engineering, Human computation and crowdsourcing, Web applications composition and mashups, SocialWeb applications, SemanticWeb, and, for the first time, also the Web of Things.