Peers become especially influential in adolescence, a developmental period marked by a nadir in school motivation. In the classroom, adolescents often engage in social comparison with their peers to ascertain their own academic competence, which can have substantial effects on their motivation and learning. The present experimental study examined how peer mindset and social comparison processes may interact to affect adolescents' learning outcomes and responses to social comparison. Participants (N = 120, M[subscript age] = 12.73 years, 58% female) created avatars to virtually represent themselves and heard growth mindset or neutral statements from purported peer avatars. They then completed a series of online, self-report surveys measuring their learning outcomes, completed problem-solving tasks, and received feedback on their and their peers' performance via a virtual leaderboard. Multivariate between-group comparison revealed growth mindset peers increased adolescents' learning outcomes, while social comparison dampened outcomes. No interactions between peer growth mindset and social comparison were found.