This study aims to examine the effects of flipped learning on L2 students' overall academic achievements through meta-analysis. Forty studies (e.g., journal articles, M.A/Ph.D. theses and conference papers) on 'flipped classroom', 'flipped learning' and 'academic achievement' were included in this meta-analysis study. The data was analyzed by using Comprehensive Meta-Analysis Software. The random effects model was used in analyzing the overall effect size and the heterogeneity of the studies included in this meta-analysis. The results revealed that flipped learning has statistically significant effect on L2 learners' academic achievements (g=1.303) compared to traditional learning approaches. This result does not differ according to publication type, educational level and four basic language skills and sub-skills, but it differs according to sample size of the selected studies.