BACKGROUND: Obesity is considered as a major health problem of children and adolescents. The present meta-analysis was conducted by extensive search of studies on the prevalence of obesity among school-aged children and youth aged 6-18 years in Iran. METHODS: All conducted cross-sectional studies on the prevalence of obesity in Iranian students in all grades were extracted, without applying any restriction on time in national and international databases including Magiran, Iranmedex, SID, Scopus, Google Scholar, and PubMed. Statistical software Stata 12 was used to analyze the data and to obtain the prevalence of obesity among Iranian students. The heterogeneity between the results was determined using statistical test I2. RESULTS: In this meta-analysis, 51 papers met our inclusion criteria and were therefore considered for the analysis. The prevalence of obesity was equal to 5.82% [95% confidence interval (CI): 5-6.66] in Iranian students. The prevalence of obesity was higher in boys than in girls (6.85% compared to 5.13%) (P = 0.300). The highest prevalence of obesity was related to students living in the North and Northwest areas with 7.07% (95% CI: 4.35-9.78). CONCLUSION: The prevalence of obesity among Iranian students is not high when compared to Western countries. However, due to lifestyle changes in recent years, it is necessary to plan intervention programs within families and schools to improve dietary patterns and physical activity of this age group.