This study examined the effects of social relationships that adolescents have at school and in the local community (classmate relationship, student-teacher relationship, and relationship with others in the local community) on their altruistic life goal for the enlarged community (general others, environment, and social inequality). To this end, this study drew on data from Korean Children and Youth Panel Survey which were collected from 9th graders in 2012. By controlling for parents-child relationships (parents’ affective support and parents’ instruction with reasonable explanation), this study investigated the influence of social relationships at school and in the local community in a more precise way. The result from multinomial logistic regressions shows that adolescents who had a more amicable relationship with classmates, a closer relationship with teachers, and a positive relationship with neighbors tended to show stronger altruistic life goals with regard to general others, environment, and social inequality. This finding identifies the possibility that positive social relationships at school and in the local community contribute to the development of altruistic life goals for enlarged community. Therefore, for adolescents to promote democratic citizenship, they should have opportunities to enjoy positive, democratic, productive relationships with others in proximal contexts.