This book constitutes the refereed proceedings of the 15th International Conference on Intelligent Human Computer Interaction, IHCI 2023, held in Daegu, South Korea, during November 8–10, 2023. The 55 full papers and 16 short papers included in this book were carefully reviewed and selected from 139 submissions. They were organized in topical sections as follows: Volume I: Natural Language and Dialouge Systems, Affective Computing and Human Factors, Human Centred AI, Human-Robot Interaction and Intelligent Interfaces and User Centred Design. Volume II: AI and Big Data, Deep Learning, Intelligent Systems, Mobile Computing and Ubiquitous Interactions and Social Computing and Interactive Elements.