Objective.- This study examined the differences in child and adolescent time use across the following three countries with distinct policy and cultural regimes: Finland, Spain, and the United Kingdom. Background.- Studying children's time use cross-nationally is urgent to better understand how societal contexts influence children's daily lives in ways that affect their future lifestyles, development, and identity formation. Yet previous studies have largely omitted this important question. Method.- The study used 2009 to 015 time-diary data on children aged 10 to 17 from Finland, Spain, and the United Kingdom (N = 3,491). Multivariate linear regression models examined (a) between-country and (b) within-country variations. Results.- Finnish children spent 153 daily minutes less with parents, 128 more with "others" and 54 daily minutes more alone when compared with Spanish children. The United Kingdom fell between Finland and Spain in children's time allocated with parents and time with "others." In family-oriented Spain, children spent more time eating; in individualistic Finland and United Kingdom, child screen-based time was highest. Parental education generally led to more time in educational activities, but with minor country variations. Maternal employment was generally not associated with child time use, except in Spain, where it led to less parent-child time. Conclusion.- The strong cross-national differences in child and adolescent time use seem only partly driven by sociostructural factors. Cross-cultural variations in family values and parenting ideologies seem to critically influence children's daily activities.