This study examined social support as a potential moderator between stress and depressive symptoms among Mexican university applicants aged 16--21 years ("N" = 6,715; "M" age = 17.9 years; 55% female). In bivariate analyses, perceived stress was associated with higher levels of depressive symptoms, and social support with lower levels of both stress and depression. Moderation analyses conducted using hierarchical multiple regressions indicated that global social support reduced the association between stress and depression. Analyses examining support from different sources (family, friends, and significant other) indicated that family support played a unique role in buffering the negative effects of stress. Findings are consistent with the stress-buffering hypothesis and confirm the importance of the family as Mexican youth enter late adolescence. (Contains 2 tables and 1 figure.)