Sibling relationships evolve into a more egalitarian relationship dynamic resembling friendships during adolescence, potentially facilitating the transfer of interpersonal skills across relationships. This study investigates cross-relationship associations in conflict resolution strategies with siblings and friends. Research on family-peer linkages, largely focused on White populations, often overlook the role of siblings in other ethnoracial contexts. Drawing on social learning theory, we examined mean-level differences on conflict resolution strategy use with siblings versus friends and how conflict resolution strategies with siblings were related to those with friends. Participants were older ( M = 15.48; SD = 1.57) and younger siblings ( M = 12.55; SD = .60) in 246 Mexican-origin families. Adolescents reported on their use of solution-oriented, nonconfrontational, and controlling strategies with one another and their best friends, which reflect varying considerations for oneself, others, and their relationship. Multilevel ANOVAs suggest that adolescents typically use more adaptive strategies with friends than with siblings. Actor-Partner Interdependence Models revealed significant positive associations between actor-reported conflict resolution strategies with siblings and friends, even when accounting for relationship intimacy and conflict, expressive personality characteristics, and familism values, suggesting congruence across relationships. Cross-strategy analyses indicated that controlling strategies with siblings were correlated with all strategies with friends, while nonconfrontational strategies with siblings negatively related to solution-oriented strategies with friends. These findings highlight how sibling and friend experiences shape adolescents’ interpersonal skills and suggest avenues for future research on the enduring impact on social development.