The transition from high school to college (TTC) is a critical period of change, the effects of which may be exacerbated for Latino students, who often face additional minority-specific stressors, such as ethnic/racial discrimination (ERD). Research has documented links between ERD and sleep outcomes in adolescents, but less is known regarding the longitudinal impacts of ERD experiences during unique risk periods (e.g., TTC). Further, despite the central role of family in Latino adolescents’ lives, less research has explored the protective role of family factors (e.g., familism, family support) in links between ERD and Latino students’ sleep health. Thus, this study examined: 1) longitudinal associations between peer- and adult-perpetrated ERD in high school and actigraphy-measured (e.g., duration, efficiency, midpoint) and subjective sleep (e.g., problems) during the first year of college among Latino adolescents, accounting for college ERD experiences, and 2) familism and family support as potential moderators of these associations. Participants were 209 Hispanic/Latino adolescents (Mage=18.10; 64.4% female; 84.7% Mexican descent; 67.9% first-generation students) assessed at two time points (i.e., last semester of high school and second semester of college). There were no longitudinal associations between high school ERD and college sleep. However, there were concurrent associations between ERD and sleep in college. Specifically, greater college peer- and adult-perpetrated ERD were associated with less duration and lower efficiency at the same time point. Further, more college adult-based ERD was additionally linked with greater sleep problems. There were no significant moderation findings; however, the interaction between high school adult-based ERD and family support predicting college sleep problems suggested that adolescents reporting low levels of adult ERD in conjunction with higher levels of family support had the fewest sleep problems. Study findings provide additional evidence that ERD from both adults and peers is associated with reduced sleep duration and quality among Latino college students and suggest that current cultural stressors may be particularly influential on sleep during major socio-contextual shifts. These findings can inform future programs (e.g., sleep interventions) that provide support for students experiencing race-based stressors, such as ERD, to promote Latino student health and well-being.