 The study of extremophiles has been revolutionary for our understanding of life on Earth. Recent breakthroughs have challenged long-held assumptions about the nature of life and its potential to survive in extreme conditions. The latest research into this area has revealed new insights into the diversity of life forms, their adaptations to extreme environments, and their potential applications in biotechnology. This special issue provides an overview of the current state of knowledge in this rapidly evolving field. This article was authored by Pablo Enrique Rampolado.