In interpersonal models of developmental psychopathology, friendships and affiliations with peers have been considered as both consequences and determinants of children's and adolescents’ internalizing behaviors and peer victimization. Longitudinal stochastic actor-oriented models (SAOMs) allow developmental researchers to disentangle peer selection processes where children or adolescents choose friends who are similar to themselves in internalizing behaviors or peer victimization from peer influence processes where children or adolescents become more similar to their friends over time in internalizing behaviors or peer victimization. This paper highlights the methods and results from a systematic review that screened 1447 empirical articles and located 28 using SAOMs to understand the interplay between peer social networks and internalizing behaviors or peer victimization. The results provide some evidence for both peer selection and influence related to depression, social anxiety, and peer victimization. Additionally, the results provide insight into directions for additional substantive and methodological research. Based on the findings of this review, future research is recommended that considers specific tests of peer selection and influence mechanisms, developmental and gender differences, individual and contextual moderators, multiplex relationships, methodological quality, and direct replication of prior studies.