This book provides a collection of papers from the Ninth Workshop on Computing: Theory and Practice, WCTP 2019 devoted to theoretical and practical approaches to computation, which was organized by four top universities in Japan and the Philippines: Tokyo Institute of Technology, Osaka University, the University of the Philippines Diliman, and De La Salle University. The proceedings provide a broad overview of recent research trends in computer science research in Asia, particularly in these two countries. The papers included in the proceedings focus on both theoretical and practical aspects of computations, such as programming language theory, modeling of software systems, applications of machine learning, empathic computing, and various applications of information technology.