OBJECTIVES: We explored the role of particular sources of social support (friends, romantic partners, family) as moderators and mediators in the associations between perceived stress and individual well-being (loneliness, depressive symptoms, and self-rated physical health). We also tested the possible moderating effect of gender to ascertain whether women and men are differentially impacted by social support's diverse sources. METHOD: Participants were 163 Latina/o emerging adults attending college (85% women; Mage = 20.2 years, range: 18-25). RESULTS: Holding perceived stress constant, friend support was negatively associated with loneliness, romantic partner support was negatively related to depressive symptoms, and family support was positively associated with self-rated physical health. Friend or romantic partner support moderated the relationships between perceived stress and loneliness, and self-rated physical health, but not depressive symptoms. Perceived stress and loneliness were indirectly and positively associated through lower friends and romantic partner supports, perceived stress and depressive symptoms were indirectly and positively related through lower romantic partner support, and perceived stress and self-rated physical health were related indirectly and negatively through lower family support. Gender moderated the relationships between family and friend support and self-rated physical health, and between friend support and depressive symptoms. Particular sources of support mediated the associations of perceived stress with well-being. CONCLUSIONS: Results highlight how social support helps Latina/o youth cope with stress and mitigate challenges associated with their college transition. Social support implications for physical and psychological health differ for male and female Latina/o college-attending emerging adults. (PsycINFO Database Record (c) 2020 APA, all rights reserved).