OBJECTIVES: To systematically review the literature about: 'What is the global estimated prevalence of dental fear in adults?'. DATA/SOURCES: Inclusion criteria were observational population-based studies reporting the prevalence or raw data of dental fear in adults (>18 years). Five electronic databases (Embase, PubMed, Scopus, Virtual Health Library and Web of Science) were searched without language restrictions up to March 2020. Two researchers independently performed the study selection, data extraction and quality assessment of the included studies. Risk of bias was performed using the Joanna Briggs Critical Appraisal Checklist for Prevalence and Incidence studies. The prevalence pooled estimates of dental fear were calculated using fixed- and random-effect models. Subgroup analyses were performed. STUDY SELECTION: The search strategy identified 4,486 studies. After removal of duplicates (1,722), title and abstract screening (2,764) and full-text reading (108), 31 publications were deemed eligible for this systematic review. Three studies presented low risk of bias and 28 studies presented high risk of bias. A total of 72,577 individuals 18 years of age or older composed the sample of this systematic review. The global estimated prevalence of dental fear and anxiety (DFA), high DFA and severe DFA in adults were 15.3 % (95 %CI 10.2-21.2), 12.4 % (95 %CI 9.5-15.6) and 3.3 % (95 %CI 0.9-7.1), respectively. Subgroup analyses showed a higher prevalence of DFA, high DFA and severe DFA among women and younger adults. The instruments used to measure dental fear also affected its prevalence. CONCLUSIONS: Dental fear and high dental fear are prevalent in adults worldwide, being more prevalent among women. CLINICAL SIGNIFICANCE: Evidence suggests fear negatively impacts dental care pattern, clinical and subjective oral health conditions. A better knowledge of the global prevalence and the factors associated with this problem will allow that prevention or even behavior modulation strategies of the fearful individual's in dental setting being carried out.