This two-volume set CCIS 2887-2888 constitutes the refereed proceedings of the Third International Conference on Sustainable Development through Machine Learning, AI and IoT, ICSD 2025, held in New Delhi, India, during June 14-15, 2025. The 56 full papers include in these volumes were carefully reviewed and selected from 252 submissions. They provide a comprehensive overview of recent research trends and technological advancements in sustainable development enabled by machine learning, artificial intelligence, and IoT. The contributions cover a broad spectrum of application domains, including energy-efficient and intelligent systems, smart and sustainable cities, environmental monitoring and protection, agriculture and food systems, and innovative healthcare solutions.