Group sports interventions have been developed to improve health-related physical fitness of overweight/obese youth. However, its benefits are not systematically documented. This study synthesizes the evidence about the effects of group sports on health-related physical fitness of overweight/obese youth. Pubmed, Web of Knowledge, Scopus, Medline, CINAHL, SportDiscus, and Academic Search Complete were searched in February 2016. Studies assessing the effects of group sports on body composition, cardiorespiratory endurance, muscle strength, flexibility, and neuromotor fitness of overweight/obese youth (aged <18years) were included. Effect sizes (ES) were calculated with Cohen's d and its 95% confidence intervals (CI). Improvements were found in (i) body composition - percentage of fat body mass (pooled ES=0.67; 95% CI=0.24-1.10) and waist circumference (ES=0.69; P=0.004); (ii) cardiorespiratory endurance - peak oxygen consumption (pooled ES=0.53; 95% CI=0.13-0.92) and (iii) muscle strength - hand grip strength (ES=0.72; P=0.003). No significant effects were found for body mass index (pooled ES=0.27; 95% CI=-0.14 to 0.69), percentage of lean body mass (ES=0.01; P>0.05), maximal power output (ES from 0 to 0.06; P>0.05), sit-and-reach test (pooled ES=0.26; 95% CI=-0.16 to 0.68) and agility test (ES=0; P=0.48). Group sports improve body composition, cardiorespiratory endurance, and hand grip strength of overweight/obese youth. Flexibility and neuromotor fitness do not seem to change following group sports.