The objective of this meta-analysis is to rigorously assess the participant effects of private school vouchers, or in other words, to estimate the average academic impacts that the offer (or use) of a voucher has on a student. This review adds to the literature by being the first to systematically review all Randomized Control Trials (RCTs) in an international context. This paper presents three meta-analytic estimates of the impacts of school vouchers: (1) just in the U.S.; (2) just outside the U.S.; and (3) globally including the U.S. and all other countries. The initial research was guided by the following question: What is the impact of private school vouchers globally on the student achievement of those students offered the vouchers? The RCTs included in this analysis were located in four countries: the United States of America, Kenya, Colombia, and India. The U.S. studies covered programs in Charlotte, North Carolina; Dayton, Ohio; Milwaukee, Wisconsin; New York City; Toledo, Ohio; and Washington, D.C. The participants in the RCTs were children who attended private schools through a school voucher. The grades analyzed ranged from K-12, although most individual RCTs included a shorter grade range in their analysis. The programs evaluated were publicly or privately funded school voucher or K-12 "scholarship" programs. The research design of the studies that inform the meta-analysis was random assignment of children to treatment and control groups. Most studies had a one-stage randomization through administration of a lottery while one study in Andhra Pradesh, India was based on a two-stage randomization (randomly assign students within randomly assigned villages). For this meta-analysis, researchers identified publications from computer and networked searches through a variety of sources. For math scores, the effect sizes are positive for twelve studies except for Rouse (1998), Bettinger (2003), and Muralidharan and Sundararaman (2015). For reading studies, the effect sizes are positive for thirteen studies except for Krueger and Zhu (2004). Overall global effect size from meta-analysis indicates null impacts on math scores [95% CI: -0.003 to 0.057 standard deviations] and positive, but small impacts on reading scores [95% CI: 0.066 to 0.127 standard deviations]. For reading outcome measures, the effect size is positive overall for studies in and outside of the U.S. The effect size is much greater for non-U.S. regions (d = 0.136) [95% CI: 0.087 to 0.185 standard deviations] than for U.S. (d = 0.071) [95% CI: 0.032 to 0.111 standard deviations]. Additionally, the effect size for privately funded vouchers (d = 0.102) [95% CI: 0.064 to 0.139 standard deviations] is more than that for publicly funded vouchers (0.087) [95% CI: 0.033 to 0.142 standard deviations]. Details on search and exclusion process, along with tables and figures, are appended.