Every two years, industry leaders and practitioners from around the world gather at the Rapid Excavation and Tunneling Conference (RETC), the authoritative program for the tunneling profession, to learn about the most recent advances and breakthroughs in this unique field. The 2023 Rapid Excavation and Tunneling Conference Proceedings includes the presentation of 133 papers divided into 20 technical sessions and include contributions from all divisions of the tunneling industry plus risk management and best contract practices. The selected papers provide a comprehensive recap of the conference while also providing a source of reference for contractors and engineers in the future. This comprehensive conference helps practicing professionals keep up with the ever changing and growing tunneling industry.