Problematic alcohol use in physicians poses a serious concern to physicians' health and their ability to provide care. Understanding the extent and characteristics of physicians with problematic alcohol use will help inform interventions. To estimate the extent of problematic alcohol use in physicians and how it differs by physician sex, age, medical specialty, and career stage (eg, residency vs practicing physician). Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) 2020-compliant systematic review, searching Medline, Embase, and PsychInfo from January 2006 to March 2020. Search terms included Medical Subject Headings terms and keywords related to physicians as the population and problematic alcohol use as the primary outcome. The quality of studies was assessed using the Newcastle-Ottawa Scale. We included articles where problematic alcohol use was measured by a validated tool (ie, Alcohol Use Disorders Identification Test [AUDIT], AUDIT Version C [AUDIT-C], or CAGE [Cut down, Annoyed, Guilty, and Eye-opener] questionnaire) in practicing physicians (ie, residents, fellows, or staff physicians). Thirty-one studies involving 51 680 participants in 17 countries published between January 2006 and March 2020 were included. All study designs were cross-sectional, self-reported surveys. Problematic alcohol use varied widely regardless of measurement method (0 to 34% with AUDIT; 9% to 35% with AUDIT-C; 4% to 22% with CAGE). Reported problematic alcohol use increased over time from 16.3% in 2006 to 2010 to 26.8% in 2017 to 2020. The extent of problematic use by sex was examined in 19 studies, by age in 12 studies, by specialty in 7 studies, and by career stage in 5 studies. Seven of 19 studies (37%) identified that problematic alcohol use was more common in males than females. Based on the wide heterogeneity of methods for included studies, limited conclusions can be made on how problematic alcohol use varies based on physician age, sex, specialty, and career stage. Studies about problematic alcohol use in physicians demonstrate a high degree of heterogeneity in terms of methods of measurement, definitions for problematic alcohol use, and cohorts assessed. Most studies are primarily self-reported, precluding the ability to determine the true prevalence among the profession. Few studies provide relevant comparisons to aid in identifying key risk groups for targeted interventions.