This article proposes ‘resonance’ as a fruitful way of conceptualising the relationship between youth and later life and reflecting on its significance: resonance is how a person’s ‘youth’ is lived with in the present of their later life. Resonance revisions youth, engaging with the complexity of its presence in the lifecourse. Relinquishing a preoccupation with continuity and linearity, youth seen from the vantage point of later life contributes fresh insights into what matters for people and how. This conceptualisation emerged from a qualitative study of women born 1939–52 which revealed that experiences attributed to the teens and early twenties have a presence in a person’s later life in ways unrecognised in established approaches, namely longitudinal life-course studies and socio-cultural approaches. These resonances are often historically inflected such that some cohorts may live with their youth in later life in ways that distinguish them from their predecessors and successors.