INTRODUCTION AND HYPOTHESIS: This study aims to systematically estimate the global prevalence of overactive bladder (OAB), identify demographic and regional factors contributing to prevalence variations, and assess trends in prevalence over the past two decades. METHODS: This cross-sectional study was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guideline. From inception to April 2024, computerized searches for OAB prevalence-related literature were conducted on PubMed, Embase, Web of Science, and Cochrane. Studies of OAB prevalence in the general population were included. Two independent researchers conducted the screening, data extraction, and quality assessment of the included studies. RESULTS: A total of 53 studies, encompassing 610,438 participants, were ultimately included in the analysis. The meta-analysis determined the global prevalence of OAB to be 20% (95% CI 0.18-0.21). Over the past 20 years, there has been an increase in OAB prevalence, rising from 18.1% (95% CI 0.13-0.23) to 23.9% (95% CI 0.19-0.29). Among women, the prevalence of OAB was 21.9% (95% CI 0.20-0.24), indicating higher rates compared to men (OR = 16.1, 95% CI 0.15-0.18). The study also found higher prevalence rates among overweight and obese individuals (OR = 18.6, 95% CI 0.13-0.24) and those aged 60 years and above (OR = 28.3, 95% CI 0.24-0.33). Middle-income countries exhibited higher prevalence rates compared to high-income countries. CONCLUSIONS: The study highlights higher risks of OAB among obese individuals, women, and the elderly. OAB prevalence has shown an increasing trend over the past 20 years.