Children with depressed parents are at greater risk of developing depression than children whose parents do not have depression. Activity scheduling has been shown to mitigate depressive symptoms; however, research has yet to fully determine what components of activities (i.e., physical activity of sports vs. socialization of organizations) impact the strength of the relationship between parental and child depressive symptoms. This study investigated the relationship between maternal and child depressive symptoms and the degree to which youth involvement in activities impacted the strength of the relationship between maternal and child depression. Participants included 116 treatment-seeking mother–child dyads (M = 10.99; SD = 2.39). Results of multiple regressions suggested that maternal depressive symptoms was a significant predictor of children’s depressive symptoms. In addition, the number of sports a child participated in was a predictor of child depressive symptoms (p = .006) and was a significant moderator of the relationship between maternal and child depressive symptoms (p = .005). Visual analysis of a regression line plot suggested that participation in a higher number of sports was associated with less severe child depressive symptoms across level of maternal depressive symptoms (i.e., high vs. low). Number of organizations and hobbies were not significant moderators of the relationship between maternal and child depressive symptoms. Results suggest that involvement in multiple sports may decrease the strength of the association between maternal and child depressive symptoms, although more research is needed to demonstrate causality. Nevertheless, this study suggests the clinical utility of increased participation in sports for children.