The existing literature provides compelling evidence on the effect of school leadership on the collective efficacy of teachers, which is highly correlated with teaching--learning outcomes. However, the results of studies that examined the relationship between these variables have not reached a consensus. Therefore, the main objective of this study is to determine the extent to which school leadership influences collective teacher efficacy through a meta-analysis. The study identified 47 research articles with a total of 25,645 respondents. The results suggest a large-level effect of school leadership behaviors on collective teacher efficacy. Moreover, three variables; "leadership style," "country culture," and "school level," moderate the effect of school leadership on collective teacher efficacy. Especially, the impact of instructional leadership is stronger than those of transformational and other types of leadership. In addition, the magnitude impact of school leadership on collectivist culture is larger than that of individualistic culture. Furthermore, the findings suggest that the main effect size of school leadership on teacher collective efficacy in high schools is greater than those in other school levels. Lastly, the paper presents the implications and limitations of this study as well as recommendations for future research.