Peers are central in shaping adolescents’ development across various domains. This research examined patterns of peer system resources and liabilities, and their association with academic adjustment. A person-centred approach, Latent Profile Analysis, was used to classify students into groups based on characteristics of the peer system: friendship quality, group, and general peer relations. Participants were 443 students in their ninth grade year, 14.7 years old on average, and 57% female. Peer system characteristics formed four profiles. The most common profile had high resources and low liabilities; the three other profiles were mixtures of moderate/high resources and low/moderate liabilities. Students with high resources/low liabilities had higher self- and teacher-reported academic engagement and GPA in fall and spring. The three mixed profiles were associated with poorer academic outcomes. These findings underscore the limitations on access to academic success for students negotiating different peer contexts.