This book constitutes the refereed proceedings of the 23rd International Conference on Practical applications of Agents and Multi-Agent Systems, PAAMS 2025, held in Lille, France, during June 25–27, 2025. The 27 full papers and 9 short papers included in this book were carefully reviewed and selected from 57 submissions. The PAAMS 2025 proceedings focus on application and validation of agent-based models, methods, and technologies in a number of key application areas, including computational social science, digital twins, simulating complex systems, agents for social good, advanced models for learning, agent-based programming, distributed data analysis, automatic planning, decision-making, social interactions, formal and theoretic models, self-adaptation, mobile edge computing, swarms, and task allocation.