Objectives Aggression is a substantial behavioral problem in children and adolescents. There has been an increasing amount of research investigating the effectiveness of mindfulness-based intervention (MBI) in reducing levels of aggression. The purpose of this review was to examine how effective mindfulness is in curbing aggressive behaviors in children and adolescents. Methods Studies were identified through searching four electronic databases (PsycINFO, CINAHL, MEDLINE, and Web of Science) with combinations of three groups of keywords supplemented with a manual search. Two independent researchers screened the searched papers, extracted data from papers, and assessed the quality of the studies. The extracted data was synthesized narratively and quantitatively. Results Eighteen studies (n = 1223) met the inclusion criteria. Three of the studies were controlled trials, seven were quasi-experimental studies, and an additional eight were single-subject design studies. Except for three studies that had unclear methodological quality, the remaining studies showed adequate research quality. Key findings highlighted evidence supporting the effectiveness of the use of MBI in children and adolescents with aggressive behavior problems. The meta-analytical results indicated that the overall effect size of MBI on aggressiveness is moderate (g = 0.48, CI95 [0.33, 0.63], p < 0.001). Furthermore, sub-group analysis estimated different effect sizes for clinical samples (g = 0.59, CI95 [0.23, 0.95], p = 0.001) and non-clinical samples (g = 0.45, CI95 [0.29, 0.62], p < 0.001). Conclusions The effectiveness of MBI on child and adolescent aggressive behavior was supported. Compared with non-clinical samples, MBI showed higher effectiveness for clinical samples. Potential mechanisms, methodological strengths and weaknesses, implications, and suggestions for future study are discussed.