Wellbeing has become a keyword in youth and social policy, a construct deployed as a measure of a good life. Often associated with physical and mental health, wellbeing encompasses numerous indicators, from subjective experiences of happiness and satisfaction to markers of economic prosperity and basic human needs of security. This article examines wellbeing as an organizing concept in discourses on young people and argues for defamiliarizing its truth claims and cultural authority by investigating what wellbeing does. We begin by examining the rise of wellbeing, drawing attention to its conceptual muddiness and ambiguity. Framed by the Foucauldian notion of problematization, the analysis proceeds along two routes: first, through an historical consideration of wellbeing as a relational concept with antecedents, focusing on 'self-esteem'; and second, through a reading of wellbeing in contemporary educational policy. Informed by Somers' historical sociology of concept formation and Bacchi's critical policy analysis, we illuminate the mixed dimensions of wellbeing's reach, placing it within longer traditions of youth studies and psy-knowledges and showing its transformative promise as well as its individualizing effects. In doing so, we elaborate a methodological approach that can be adapted to examine other keywords in youth studies and social policy discourse.