This book constitutes the refereed proceedings of the 19th International Conference on Metaverse, METAVERSE 2023, held in Honolulu, HI, USA, during September 23-26, 2023. The 9 full papers and 3 short papers included in this book were carefully reviewed and selected from 15 submissions. They were organized in topical sections as follows: answer set programming; metaverse engineering foundations and applications, with a focus on novel approaches for engineering requirements, design and architectures, testing, maintenance and evolution, model-driven development, software processes, metrics, quality assurance and new software economics models, search-based software engineering, benefiting day-to-day services sectors and derived through experiences, with appreciation to scale, pragmatism, transparency, compliance and/or dependability.