BackgroundParental influence on children's internalizing symptoms has been well established; however, little is known about the underlying mechanisms. One possible mechanism is child emotion regulation given evidence (a) of its associations with internalizing symptoms and (b) that the development of emotion regulation during childhood and adolescence is influenced by aspects of the family environment. This meta‐analysis aimed to systematically investigate the mediating role of child emotion regulation in the relationship between various family factors and internalizing symptoms in children and adolescents.MethodsWe searched Medline, Embase, PsychInfo, and Web of Science for English articles up until November 2022. We included studies that examined child emotion regulation as a mediator between a family factor and child/adolescent internalizing symptoms. Random‐effects models were used to calculate pooled indirect effects and total effects for nine family factors. Heterogeneity and mediation ratio were also calculated.ResultsOf 49 studies with 24,524 participants in this meta‐analysis, family factors for which emotion regulation mediated the association with child/adolescent internalizing symptoms included: unsupportive emotion socialization, psychological control, secure attachment, aversiveness, family conflict, parent emotion regulation and parent psychopathology, but not supportive emotion socialization and behavioral control.ConclusionsVarious family factors impact children's emotion regulation development, and in turn, contribute to the risk of internalizing symptoms in young people. Findings from this study highlight the need for interventions targeting modifiable parenting behaviors to promote healthy emotion regulation and better mental health in children and adolescents.