With the ongoing development of immersive technologies, growing degrees of design flexibility, and integrated communicative tools, the metaverse presents new possibilities for facilitating language learning opportunities through meaningful social interactions. As the metaverse is still emerging, the edited volume identifies the key elements of metaverse-based language learning and teaching by placing them in the context of established theories and practices in second language acquisition. It also presents metaverse platforms and tools, and provides examples of how they might be used in the field of English Language Education. The volume is divided into four parts (Foundations, Practical Applications, Socio-Emotional, Ethical and Sustainable Dimensions, and Future Directions), consisting of 13 internationally contributed chapters that address various aspects of the metaverse-based language teaching and learning. The volume provides valuable insights for language educators, researchers, and learners, and aims to enrich the language learning and teaching landscape in an increasingly digital world.