The purpose of this study was to examine the overall effectiveness of the flipped classroom on students' learning achievement and motivation. Data were collected from three databases, which include Web of Science, Scopus, and Eric. The present meta-analysis synthesized the findings of 95 studies with 15,386 participants published from 2013 to 2019. The results revealed that the flipped classroom approach had a moderate effect size for learning achievement and learning motivation. The effect sizes of 12 moderators, including sample level, sample size, learning domain, the flip classroom model, research design, intervention duration, teaching method in the class, sample region, interactions in a pre-class and face-to-face class, tools in pre-class, and resources in pre-class were also analyzed. The results indicated that sample size, intervention durations, and sample regions significantly moderated the effect sizes. The findings of this study are discussed in-depth, together with the implications for practices on the use of the flipped classroom approach.