The family and classroom are important contexts that can contribute to the socialization of ethnic prejudice. However, less is known about their unique, relative, and synergic contributions in influencing youth's affective and cognitive prejudice. The current longitudinal study examined these processes and possible moderators among 688 Italian youth (49.13% girls; M[subscript age] = 15.61 years), their parents (n[subscript mothers] = 603, n[subscript fathers] = 471; M[subscript age] = 49.51 years), and classmates between January/February 2022 and January/February 2023. Cross-lagged panel models highlighted that parents and classmates exert unique and relative influences on different dimensions of adolescents' prejudice. Additionally, different interaction effects also emerged for affective (i.e., adverse compensatory effect) and cognitive (i.e., amplifying effect) prejudice. Thus, adolescents draw from the multiple contexts of development to orient themselves in the social world.