This book constitutes the proceedings of the Third International Conference on Artificial Intelligence: Towards Sustainable Intelligence, AI4S 2025, held in Dayton, USA, during October 2-3, 2025.The 11 full papers and 2 short papers included in this book were carefully reviewed and selected from 52 submissions. These papers focus on the implementation and accountability of Artificial Intelligence systems, including topics such as Climate Risk Management, Healthcare Efficiency, Trustworthy AI in Health and much more.