This volume addresses important questions related to the well-being and quality of life of emerging adults during crisis periods. It discusses the particular challenges that emerging adults face during a global or local crisis, the psychosocial resources they mobilize to overcome them and to flourish, the well-being indicators pertinent to youth development across various life domains, and the strategies to promote positive youth development and well-being under conditions of crisis. The volume examines these questions from an international and interdisciplinary point of view, collecting contributions mainly from psychology, but also education, economics, and sociology. It includes novel quantitative and qualitative research, intervention studies, critical reviews, and conceptual chapters. This makes it an essential read for scholars of positive development in emerging adulthood under crisis, as well as a relevant and accessible source of information for discerning lay readers. The specific focus of the majority of contributions on the Covid-19 pandemic makes this volume highly topical. Its focus on both well-being dimensions and problems related to crises offers a deeper understanding of the cultural similarities and differences in individual and collective challenges and resources across world regions. The volume investigates various facets of well-being, including daily experiences, relationships, purpose and growth, learning activities, and achievements. Evidence derived from the contributions to this volume can prove valuable for handling future crises through targeted interventions and programmes in different contexts and life domains.