This book constitutes the refereed proceedings of the 13th International Conference on Computational Collective Intelligence, ICCCI 2021, held in September/October 2021. The conference was held virtually due to the COVID-19 pandemic.
The 58 full papers were carefully reviewed and selected from 230 submissions. The papers are grouped in topical issues on knowledge engineering and semantic web, social networks and recommender systems, collective decision-making, cooperative strategies for decision making and optimization, data mining and machine learning, computer vision techniques, natural language processing, Internet of Things: technologies and applications, Internet of Things and computational technologies for collective intelligence, computational intelligence for multimedia understanding.