This book constitutes the proceedings of the 6th International Conference on Blockchain, ICBC 2023, held as part of the Services Conference Federation, SCF 2023, held in Honolulu, HI, USA, during September  23–26, 2023.   The 9 full papers presented in this book were carefully reviewed and selected from 18 submissions. The conference focuses on new blockchain architecture, platform constructions, blockchain development, and blockchain services technologies as well as standards and blockchain services innovation lifecycle, including enterprise modeling, business consulting, solution creation, services orchestration, services optimization, services management, services marketing, and business process integration and management.