--- - |2 Abstract Mounting evidence indicates that deficits in positive affect (PA) regulation are implicated in youth depression. Although parental responses to youths’ PA expressions have been linked to youth regulation of negative affect, no study has directly examined whether parental responses are linked with youth PA regulation strategies. The present study utilized a novel observational measure to test whether maternal active‐constructive responses to youths’ PA were uniquely associated with youth effective PA regulation strategies and, subsequently, depressive symptoms. Ninety‐two adolescents between the ages of 11 and 18 (Mage = 14.22, Girls = 62%) and their primary female caregivers (Mage = 41.40, 88% biological mothers) completed a series of questionnaires and engaged in a Plan a Day Trip interaction task. Results revealed that observed maternal active‐constructive responses to adolescents’ PA were uniquely associated with adolescents’ effective PA regulation strategies which, in turn, were related to lower depressive symptoms. These findings underscore the importance of parental responses to PA when sharing positive experiences for specifically targeting adolescents’ responses that generate and sustain PA. - Social Development, EarlyView.