This meta-analytic study estimated the correlations among metacognition, intelligence, and academic performance. Metacognition is higher order cognition and one of the most significant predictors of academic performance. The purpose of this study was to examine the degree to which metacognition predicted academic performance when controlling for intelligence. The analysis of 149 samples from 118 articles revealed that, overall, metacognition weakly correlated with both academic performance and intelligence, and that these relationships were moderated by the type of measurement of metacognition. Furthermore, it was found that metacognition predicted academic performance when controlling for intelligence. Our findings indicate the importance of metacognition in educational practice and provide guidance for assessing metacognition in future research.