This book constitutes the refereed proceedings of the 29th International Conference on Collaboration Technologies and Social Computing, CollabTech 2023, held in Osaka, Japan, during August 29–September 1, 2023, in hybrid mode.The 8 full papers presented in this book together with 12 short papers were carefully reviewed and selected from 31 submissions. The papers focus on innovative technical, human and organizational approaches to expand collaboration support including computer science, management science, design science, cognitive and social science.