This study was designed to examine associations among parents' familism values, adolescents' cultural resources, and externalizing behavior among Latinx youth in the Midwestern United States. Participants were 267 Latinx adolescents (M age = 15.58 years; SD = 1.28 years; 45% girls; 82.8% Mexican American) and their mothers/mother figures who completed individually administered interviews comprised of standardized measures. Structural equation modeling was used to test several alternative mediational models in which youth ethnic identity and familism values served as potential cultural mechanisms linking parents' familism values to lower levels of youth externalizing behavior. Results showed that mothers' familism values were positively associated with youth ethnic identity which was positively associated with youth familism values; in turn, youth familism values were inversely associated with externalizing behavior. The findings did not differ by youth gender or nativity (U.S.-born vs. foreign-born youth). These findings provide support for cultural resilience perspectives by highlighting the protective role of ethnic identity and familism values among U.S. Latinx adolescents. (PsycInfo Database Record (c) 2024 APA, all rights reserved).