This meta-analysis determined game-based learning's (GBL) overall effect on students' computational thinking (CT) and tested for moderators, using 28 effect sizes from 24 studies of 2,134 participants. The random effects model results showed that GBL had a significant positive overall effect on students' CT (g = 0.677, 95% confidence interval 0.532-0.821) with significant heterogeneity among effect sizes. Among game types, role-playing yielded the largest GBL effect size, followed by action, puzzles, and adventures. Moreover, the effect of GBL on CT was weaker among students in countries that were more individualistic than others. Lastly, interventions between four hours and one week showed the largest GBL effect size, followed by those over four weeks, up to four hours, and between one week and four weeks.