Telomere length is an important indicator of aging and related diseases. Identifying risk and protective factors for telomere shortening early in life among youth from Mexican immigrant families is critical for reducing ethnic health disparities. This study investigates how familial environmental factors (i.e., culture-general and culture-specific parenting and parentification experiences) shape individual differences in the association between depressive symptoms and telomere length. Adolescents from immigrant families (n = 325; M = 12.81) self-reported their perceptions of maternal hostility, warmth, cultural socialization, and parentification experiences across three waves during adolescence, as well as depressive symptoms in late adolescence (M = 17.61). Youth also provided dried blood spots for telomere length assessment at Wave 3. Moderation models were conducted in Mplus 8.3 with basic sociodemographic variables and BMI controlled. Maternal hostility, cultural socialization, and parentification during adolescence, but not maternal warmth, were critical family context factors impacting biological (i.e., telomere length) responses to depressive symptoms. Higher depressive symptoms were related to shorter telomere length in late adolescence only for youth who experienced high levels of maternal hostility, lower cultural socialization, or lower parentification experiences during adolescence. This study highlights the importance of cultivating cultural assets through culturally specific parenting and family experiences during adolescence, demonstrating their role in mitigating the link between depressive symptoms and accelerated cellular aging as shown by telomere length.