Guided by concepts from a relational developmental perspective, this study examined intra- and interpersonal associations between self-esteem and depressive symptoms in a sample of 1,407 couples surveyed annually across 6 years in the Panel Analysis of Intimate Relations and Family Dynamics (pairfam) study. Autoregressive cross-lagged model results demonstrated that self-esteem predicted future depressive symptoms for male partners at all times, replicating the vulnerability model for men (low self-esteem is a risk factor for future depression). Additionally, a cross-partner association emerged between symptoms of depression: Higher depressive symptoms in one partner were associated with higher levels of depression in the other partner one year later. Finally, supportive dyadic coping, the support that partners reported providing to one another in times of stress, was tested as a potential interpersonal mediator of pathways between self-esteem and depression. Female partners' higher initial levels of self-esteem predicted male partners' subsequent reports of increased supportive dyadic coping, which, in turn, predicted higher self-esteem and fewer symptoms of depression among female partners in the future. Male partners' initially higher symptoms of depression predicted less frequent supportive dyadic coping subsequently reported by female partners, which was associated with increased feelings of depression in the future. Couple relations represent an important contextual factor that may be implicated in the developmental pathways connecting self-esteem and symptoms of depression.