OBJECTIVE: To clarify who generalist physicians are and what characterizes their practice. DATA SOURCES: MEDLINE, PsycInfo, SocINDEX, Embase, Ovid HealthSTAR, Scopus, and Web of Science. STUDY SELECTION: Empirical studies (quantitative, qualitative, mixed methods) that described the attributes of generalist physicians across various disciplines in the clinical literature. SYNTHESIS: A total of 262 studies from 25 countries met inclusion criteria. Forty-seven percent of studies lacked essential participant information. The remaining studies primarily framed generalism in terms of an absence of specialist training, reflecting a "deficit model" of care. We identified 4 archetypes of generalist practice: broad-based knowledge, generalism as adaptive expertise, generalism as integrative expertise, and generalism as interpretive expertise. CONCLUSION: Generalism lacks a consistent meaning across clinical disciplines in medicine. Four archetypes of practice are proposed to promote cross-disciplinary dialogue and guide the design of future health care systems and professional roles.