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.