There is limited research on ethnic-racial socialization outside the family context (e.g., in peer groups). Using two-week, daily data from 177 U.S. ethnic-racial minority 9th graders in 2017-2020 (M[subscript age] = 14.48 years old; 51% females; 52% Black, 20% Latinx, 10% Asian American, 6% Native American, and 12% Other), this study tested a transactional model of family and peer ethnic-racial socialization, identity, and discrimination. Bidirectional associations were observed between family and peer cultural socialization across days ([beta]s = 0.09-0.10). Peer but not family cultural socialization promoted adolescents' ethnic-racial identity on the next day ([beta]s = 0.07-0.10). Ethnic-racial discrimination predicted greater next-day family ethnic-racial socialization (cultural socialization, preparation for bias; [beta]s = 0.08-0.11), whereas family and peer ethnic-racial socialization predicted next-day discrimination ([beta]s = 0.11-0.18). The differential roles of family and peer ethnic-racial socialization are discussed.