Depressive symptoms are one of the mental health problems among Korean American (KA) youth. Although several studies examined mental distress among KA youth, few have examined the associations between different familial factors, negative emotionality, and depressive symptoms among them, especially using longitudinal data. Drawing on the Triadic Model of Family Process (TMFP), this study examined the longitudinal associations between Korean-specific aspects of familial factors and depressive symptoms among KA youth and the mediation role of negative emotionality in the relationships. Using KA youth and parent data from the Midwest Longitudinal Study of Asian American Families (MLSAAF) project, path analyses revealed that family enmeshment and youth-reported intergenerational conflict were associated with youth depressive symptoms, with negative emotionality serving as a mediator. The findings suggest that interventions aimed at reducing negative emotionality and improving parent-youth relationship quality and family boundaries could be helpful in reducing youth depressive symptoms.