Extrinsic interpersonal emotion regulation (IER), or how people regulate others’ emotions, has been examined as a risk factor for adolescent depression. Although IER and depression development are transactional, dyadic processes, previous work has almost exclusively focused on how parental IER is associated with adolescent depression. The association between parental IER and parental depression, and the associations between adolescent IER and adolescent and parent depression, have received little attention. Moreover, most studies have focused on the regulation of negative but not positive affect. We address these gaps by examining associations between parent and adolescent IERs and depressive symptoms using the Actor Partner Interdependence Model framework. For 28 days, 112 parent-adolescent dyads (adolescents aged 12-18 years) completed a dyadic daily-diary, reporting IER strategies employed in response to dyad members’ positive and negative affect and their own depressive symptoms. Our results, based on 5442 data points, show that the use of positive- and negative-affect-worsening IERs is associated with more depression in the regulator (be it parent or adolescent). Surprisingly, parents’ use of more negative-affect improving IERs was associated with more depression. Finally, adolescents’ use of positive-affect improving IERs was associated to their own decreased depression. Overall, parents (vs. adolescents) used more negative- and positive-affect-improving extrinsic IERs, whereas adolescents used more positive-affect-worsening extrinsic IERs. Our results highlight the importance of using dyadic designs in studying depression and IER as well as the need to consider who is regulating, the valence of the affect regulated, and the type of strategy used.