HIV drug resistance (HIVDR) can compromise the effectiveness of antiretroviral therapy (ART) in reducing HIV incidence and HIV-associated morbidity and mortality. Minimizing the spread of HIVDR is a critical aspect of the broader global response to antimicrobial resistance. WHO recommends that countries routinely implement nationally representative HIVDR surveys. The WHO HIV drug resistance report 2021 shows substantial progress in the implementation of HIVDR surveillance. Between 2014 and 2021, 56 countries implemented HIVDR surveys using WHO-recommended methods. The HIV drug resistance report 2021 summarizes findings from 38 countries that had finalized the surveys by the time of this report and shared data with WHO.