This study is a meta-analytical study that examines the effectiveness of gamification in learning performance in educational settings (n = 29; year-span = 2011-2019). Specifically, it aimed to investigate (a) whether gamification could improve learning performance, and (b) whether peer interaction (i.e., peer competition and peer collaboration) moderated the effectiveness of gamification in learning performance. Results from random-effects models showed significant effects of gamification in learning performance (g = 0.595, 95% CI [0.432, 0.758], N = 3515). This effect remained robust after excluding outliers and was stable in a sub-split analysis that excludes studies with low methodological rigor (i.e., studies with pre-post test design). Subgroup analyses revealed a moderating effect of peer competition in gamification in learning, suggesting that competitive games were better than non-competitive games for promoting learning performance in educational settings. However, this effect was not robust and no evidence of subgroup differences were found in the sub-split analysis. Peer collaboration did not moderate the effectiveness of gamification in learning as no subgroup differences were found between collaborative games and non-collaborative games. The effectiveness of games that were both competitive and collaborative did not differ from those that were only competitive. Other moderators such as education level and research design were also investigated. No subgroup differences were found for these two moderators. Educational implications and limitations were further discussed.