Sleep is vital for health and well-being, and familial relationships may impact sleep health. This study investigated the associations between sleep health and familial social support, familial intragroup marginalization, familial conflict, and living environment (i.e., living with parent(s) or legal guardian(s)) among Hispanic adults. Hispanic adult college students (n = 455) completed a survey assessing demographics, sleep quality, and familial social support, intragroup marginalization, and conflict. One hierarchical multiple linear regression model assessed the associations between these familial factors, living environment, and sleep quality. Results indicated that poorer sleep quality was associated with greater familial conflict in the full hierarchical regression model (i.e., Step 6). In Step 2 though, poorer sleep quality was inversely associated with familial social support, yet this association disappeared once familial intragroup marginalization was entered. Post-hoc mediation analysis revealed that familial social support was inversely indirectly associated with sleep quality through familial intragroup marginalization and conflict serially. Living environment did not moderate any relationships between familial factors and sleep quality. That familial social support was initially associated with enhanced sleep quality until familial intragroup marginalization was considered suggests that familial negativity may have a greater impact on sleep health than familial social support. Further, familial social support may influence sleep quality through familial negativity. Familial conflict may be particularly detrimental for sleep health. Clinical implications are discussed. Longitudinal studies are warranted to assess temporality.