A recurrent dimension occurring in wellbeing models pertains to positive relationships of individuals. Yet there is little information elucidating the link between positive relationships and subjective wellbeing in different cultures. Thus, the aims of this paper were (1) to examine whether there is an association between positive relationships and adolescent wellbeing across several culturally distinct countries and (2) explore whether the association between positive relationships and adolescent wellbeing differed for these countries along the cultural dimensions of individualism/collectivism and indulgence/restraint. Well-being measures were obtained from the large-scale assessment PISA 2018 and cultural dimensions indices were obtained. The results provide compelling evidence that positive relationships are positively associated with both affective and eudemonic wellbeing. Furthermore, there may be a greater association between positive relationships and positive affect in collectivist-indulgent countries than in collectivistic restraint countries. The study furthers our understanding of adolescent wellbeing across different cultural dimensions.