Background. The effect of life stress on suicidal symptoms during adolescence is well documented. Stressful life events can trigger suicidality, but most adolescents are resilient and it is unclear which factors protect against the deleterious impact of stress. Social support is thought to be one such factor. Therefore, we investigated the buffering effect of specific sources of social support (parental and peer) on life stress (interpersonal and non-interpersonal) in predicting suicidal symptoms during adolescence. In order to test the specificity of this stress buffering, we also examined it with regard to dysphoric mood. Method. Data come from the Adolescent Development of Emotions and Personality Traits (ADEPT) Project, a cohort of 550 adolescent females aged 13.5–15.5 recruited from Long Island. Self-reported social support, suicidality, and dysphoria were assessed at baseline and suicidality and dysphoria were assessed again at 9-month follow-up. Life stress was assessed by interview at the follow-up. Results. High levels of parental support protected adolescent girls from developing suicidal symptoms following a stressor. This effect was less pronounced for peer support. Also, social support did not buffer the pathogenic effects of noninterpersonal stress. Finally, social support did not buffer the effect of life stress on dysphoric symptoms. Conclusions. Altogether, our results highlight a distinct developmental pathway for the development of suicidal symptoms involving parental support that differs from the development of dysphoria, and signifies the importance and specificity of social support in protecting against suicidality in adolescent girls.