This two-set volume LNAI 16138-16139 constitutes the refereed proceedings of the 17th International Conference on Computational Collective Intelligence, ICCCI 2025, held in Ho Chi Minh City, Vietnam, during November 12–15, 2025.The 67 revised full papers presented in these proceedings were carefully reviewed and selected from 290 submissions. The papers are organized in the following topical sections:Part I: Collective Intelligence and Collective Decision-Making; Co-operative Strategies for Decision-Making & Optimisation; Natural Language Processing; Knowledge Engineering & Industry 4.0 Applications; Data Mining & Machine Learning.Part II: Social Networks and Intelligent Systems; Cyber-Security, Blockchain & IoT; Computational Intelligence in Medical Applications; Computational Intelligence for Digital Content Understanding.