Objectives:The purpose of the current study was to consider the omnibus magnitude and direction of treatment effects associated with parent-inclusive interventions (PII) when compared to no treatment and nonparent-inclusive interventions (NPII) alternatives as well as sample and study characteristics associated with observed treatment effects. Method: We compared the treatment effects of child counseling interventions involving parents to NPII using meta-analysis of 59 randomized controlled studies found through four academic databases. Studies were included if they were published in English and between 1995 and 2019 in peer-reviewed and academic capstone projects, implemented randomized controlled trial methodology, participants were children ages 3-11, data were associated with primary studies, and they included some aspect of parental intervention. Analysis included synthesis of Hedge's g effect size, heterogeneity analysis, and moderator analysis. Results: The 59 studies included in the analysis yielded 5,317 participants with a mean age of 7.57. Participants predominantly identified as White (74%), female (58%), and 59% of the sample were eligible for free or reduced school lunch. Results suggested that those who received parent-inclusive treatment reported fewer symptoms as compared to those who received no treatment with a medium effect size (−0.540, 95% confidence interval, CI [−0.679, −0.400], τ 2 = 0.081, p , .001). The 60 effect sizes included in the analysis of associations between parent-inclusive and nonparent-inclusive treatment outcomes (N = 45) yielded a mean effect size of −0.322, 95% CI [−0.456, −0.189], τ 2 = 0.166, p , .001, indicative of a small effect size and suggesting participants who received PII tended to report fewer symptoms at the end of treatment when compared to those who received NPII. Furthermore, presenting concern, treatment modality, and race and ethnicity of participants statistically significantly moderated the mean effect size. Specifically, studies that involved diverse clients outperformed studies with more homogenous samples, and treatments targeting symptoms of anxiety and autism spectrum disorder yielded higher effect sizes than other presenting concerns. Interventions taking place in schools or inpatient settings outperformed other settings, and individual and family modalities outperformed group and multimodal approaches. Age, gender, and type of parent involvement did not yield statistically significant differences. Discussion: This study suggests that therapy treatments that involve parents are more effective in treating child mental health symptoms than treatments that do not involve parents. Implications are especially noteworthy for mental health therapists working with children with anxiety or autism spectrum disorder, diverse client populations, and those working in schools and inpatient settings. The demographics of participants in this study limit generalizability to older children and adolescents as well as more diverse populations. Future studies would be...