Youth well-being is a multi-dimensional construct encompassing the physical, mental, social, and developmental health and flourishing of individuals during adolescence and young adulthood. As a research concept, it systematically investigates the factors influencing these domains and their interrelationships. This academic field investigates the determinants, experiences, and outcomes related to young people's health, safety, positive relationships, educational attainment, civic engagement, emotional regulation, and overall life satisfaction. It is characterized by its dynamic nature across the developmental trajectory, its sensitivity to diverse socio-cultural and environmental contexts, and its conceptualization as more than merely the absence of negative states, but also the presence of positive capabilities and functioning. Its significance lies in informing evidence-based policies, interventions, and support systems aimed at promoting positive developmental trajectories, mitigating risks, and optimizing the life chances of young people globally.