This book gathers high-quality papers presented at the Ninth International Conference on Smart Trends in Computing and Communications (SmartCom 2025), organised by Global Knowledge Research Foundation (GR Foundation) from 29 to 31 January 2025 in Pune, India. It covers state-of-the-art and emerging topics in information, computer communications, and effective strategies for their use in engineering and managerial applications. It also explores and discusses the latest technological advances in, and future directions for, information and knowledge computing and its applications.