This book constitutes the refereed proceedings of the 9th Joint International Conference on Serious Games, JCSG 2023, held in Dublin, Ireland, during October 26–27, 2023. The 18 full papers presented together with 9 short papers and 14 poster papers were carefully reviewed and selected from 53 submissions. They are grouped into the following topics: technology and systems; theoretical and design aspects; health and wellbeing; extended realities; soft and social skills; academic skills; and posters and exhibits.