Polycystic ovary syndrome (PCOS) is the most common metabolic disorder among women of reproductive age. Many factors are involved in the development of PCOS, among which genetic predisposition is probably the main contributor that is also influenced by lifestyle and environmental factors. This study aims to determine the prevalence of PCOS in different continents based on Rotterdam, AES and NIH diagnostic criteria. We conducted a systematic review and meta-analysis to evaluate the prevalence of polycystic ovary syndrome in women according to (Preferred Reporting Items for Systematic Review and Meta-Analysis) PRISMA guidelines. PubMed, Scopus, Science Direct, Web of Science and Google Scholar databases were comprehensively searched until February 2021 for relevant articles. Heterogeneity between the studies was assessed using the I2 index. Begg and Mazumdar's test was used to evaluate publication bias. A total of 35 studies with 12,365,646 subjects were retrieved. The mean age ranged from 10-45years. Global prevalence of PCOS was 9.2% (95% CI: 6.8-12.5%) based on meta-analysis, our results showed that the global prevalence of PCOS was 5.5% (95% CI: 3.9-7.7%) based on NIH criteria, 11.5 (95% CI: 6.6-19.4) based on Rotterdam criteria, and 7.1% (95% CI: 2.3-20.2%) based on AES criteria. According to self-report subgroup analysis, the prevalence of PCOS was found to be 11% (95% CI: 5.2-21.8%). Based on the results of the present study, the prevalence of PCOS in the world was 9.2% (95% CI: 6.8-12.5%). According to the results of the present study and the high prevalence of PCOS, especially in the Africa continent, it is necessary for health systems to implement measures to timely prevent and treat this syndrome.