Ethnic-racial identity (ERI) development is a central developmental process for youth of color. Although a great deal of research establishes the importance of cultural socialization by parents to the development of ERI, limited empirical work has examined peers’ role in these processes. This study uses 4 cross-sectional data sets (N = 127, 312, 257, and 238, mean age = 17.96–18.24) followed by a meta-analytic summary to test a path model of ERI development and parent and peer cultural socialization and their associations with psychological adjustment in a diverse sample of emerging adults. The final sample size adjusted meta-analytic model indicated that parent ethnic socialization predicted both ERI exploration and commitment while only peer preparation for bias predicted ERI commitment. In turn, ERI commitment and exploration predicted more positive mental health. The findings of this study highlight the importance of both parents and peers to cultural socialization processes during emerging adulthood. In particular, this study suggests that the messages peers impart about prejudice play a unique role in the development of ERI. The findings have important implications about the unique role peers play in communicating messages about prejudice as well as for ERI and the psychological adjustment of youth of color at this developmental stage. Additionally, these cross-sectional findings provide a preliminary but robust model from which researchers can frame future longitudinal work in this area.