This book constitutes the proceedings of the Third CSIG Conference on Emotional Intelligence, CEI 2025, held in Shenzhen, China during December 5-7, 2025. The 21 full papers included in this book were carefully reviewed and selected from 79 submissions. The CEI 2025 conference focused on frontier research topics and the latest technological advances in affective computing and artificial intelligence, highlighting the applications of emotional intelligence across multiple disciplines, domains, and real-world scenarios.