Despite ample research on empathy development, its social origins have been understudied, particularly in the context of peer relations. This two-wave study of Swedish adolescents (N = 318; MageT1 = 16.28, SD = .49; 55% females) examined longitudinal associations between youth friendships and empathy. The results showed that adolescents befriended peers with similar levels of empathy and that, controlling for the initial similarity in empathy, youth who had more empathic friends increased in empathy over time compared with youth with less empathic friends. These selection and influence effects were comparable for the affective and cognitive empathy components (i.e., empathic concern and perspective taking). These results provide strong evidence for the role of friendships in the development of empathy. They underscore the importance of peer-based, social-emotional programs to foster adolescent empathy. (PsycInfo Database Record (c) 2022 APA, all rights reserved).