•Polypharmacy was observed 37 % of the population and 59 % among the frail population.•Polypharmacy was higher among those > 65, outpatients, and inpatients.•High polypharmacy in frail older calls for action from policymakers. Limited comprehensive evidence exists on the global prevalence of polypharmacy. This knowledge gap contributes to increased healthcare system costs and related public health concerns. Thus, we aimed to synthesize the current evidence on polypharmacy prevalence and associated factors in the general and older populations using an umbrella review. Our primary outcomes were global prevalence and related indicators of polypharmacy. We systematically searched Google Scholar, PubMed/MEDLINE, Embase, and CINAHL for studies published between the inception of each database until April 30, 2023. Eleven meta-analyses incorporating 295 studies and 59,552,762 participants from 41 countries across six continents were identified. The global prevalence of polypharmacy in the general population is 37 %, with higher rates in older individuals (45 %), outpatients (48 %), and inpatients (52 %). North America showed a higher prevalence (52 %) than Asia (36 %) and Europe (36 %). Among frail elderly individuals, the prevalence of polypharmacy is 59 %, with the highest rates in Europe (68 %) and hospital settings (71 %). The global prevalence of polypharmacy and its associated factors in older adults present a complex, multifaceted, and conflicting picture. Understanding the prevalence of polypharmacy and its associated factors may help reduce the number of multidrug prescriptions.