AbstractBackground and aimsThis narrative review aims to highlight key insights from qualitative research on drug use and drug users by profiling a selection of classic works.MethodsConsensus methods were used to identify and select four papers published in 1938, 1969, 1973 and 1984 considered to be classics.ResultsThese landmark qualitative studies included the first account of addiction as a social process, demonstrating that people have meaningful responses to drug use that cannot be reduced to their pharmacological effects; the portrayal of inner‐city heroin users as exacting, energetic and engaged social agents; identification of the interactive social learning processes involved in becoming a drug user; the application of the ‘career’ concept to understanding transitions and trajectories of drug use over time; and the articulation of a framework for understanding drug use that incorporates the interaction between pharmacology, psychology and social environments.ConclusionsThese classic sociological and anthropological studies deployed qualitative research methods to show how drug use is shaped by complex sets of factors situated within social contexts, viewing drug users as agents engaged actively in social processes and worlds. Their findings have been used to challenge stereotypes about drug use and drug users, develop a deeper understanding of drug use among hidden, hard‐to‐research and under‐studied populations, and provide the foundations for significant developments in scientific knowledge about the nature of drug use. They continue to retain their relevance, providing important correctives to biomedical and behaviourist paradigms, reminding us that drug use is a social process, and demonstrating how the inductive approach of qualitative research can strengthen the way we understand and respond to drug use and related harms.