This book contains original, peer-reviewed research articles from 4th International Conference on ICT for Digital, Smart, and Sustainable Development (ICIDSSD 2025), organized by Jamia Hamdard, Delhi, India, during 22–23 April 2025. It includes most recent research trends and advancements in sustainable computing, sustainable energy consumption, governance, sustainability and security, human-built systems for sustainable development, sustainable IoT and cyber physical systems, big data analytics, data science and IoT, cloud computing, and artificial intelligence.