BACKGROUND: The emergence of COVID-19 resulted in a substantial loss of education because of global school closures. Face masks are a potential measure to restrain the COVID-19 spread; therefore, this paper evaluated the effectiveness of face masks in reducing COVID-19 incidence in school settings. METHODS: A systematic review was conducted by searching the literature in the Cochrane COVID-19 Study Register and the World Health Organization COVID-19 global literature. Data were summarized in tabular forms, and the findings were presented as narrative synthesis. RESULTS: A total of 15,709 records were retrieved. The screening and selection led to the inclusion of 12 observational and 2 quasi-experimental studies. Nine studies were conducted in different states, counties, or districts of the United States, and the remaining 5 were reported from Germany, Finland, Spain, and the United Kingdom. The results of 10 out of 14 studies favored mask use in reducing school COVID-19 incidence. Three studies found no link between mask use and COVID-19 incidences, whereas 1 quasi-experimental study noted a higher COVID-19 incidence with mask use in students aged 6-11 years than no use of mask among preschool children aged 3-5 years. CONCLUSION: Mask mandates may lessen the incidence of respiratory infectious diseases in school settings during a pandemic; more well-designed studies are warranted to clarify further the evidence regarding mask use in school settings.