Aims/hypothesis <p>Despite evidence documenting high prevalence of type 2 diabetes among several Indigenous populations, a comprehensive systematic review of type 2 diabetes among global Indigenous Peoples has not been recently conducted. Our aim was to report region-, time-, age- and sex-specific type 2 diabetes prevalence among Indigenous adult populations globally.</p> Methods <p>MEDLINE, Embase and CINAHL were searched for English-language studies published between 1 January 1980 and 3 March 2023. Studies reporting type 2 diabetes prevalence and/or cases of diabetes among global Indigenous adult populations aged 18 years and older were included. Type 2 diabetes prevalence data were extracted for the overall Indigenous population, sex, age group and year. Summaries of extracted data were tabulated, and are presented using comprehensive tables and figures. A modified Newcastle–Ottawa quality assessment scale reflective of Indigenous-specific criteria was applied to assess paper quality.</p> Results <p>The search identified 2332 studies, of which 202 met the inclusion criteria. The included studies represented at least 187 Indigenous populations from 37 countries, although the exact number of populations is approximate, as some studies did not name specific Nations/Tribes/Groups for populations from different geographic regions. Diabetes prevalence ranged from 0 to 40%, with a mean of 73% of Indigenous populations reporting type 2 diabetes prevalence above the estimated global prevalences for every decade between 1980 and 2020. Prevalence increased over time and with age for many populations, with the highest reported prevalence (50.5%) in the 45–54 year age group. Type 2 diabetes prevalence was notably high among Indigenous women, with 73% of studies reporting higher prevalence for Indigenous women than for Indigenous men. Potential limitations include publication bias, which may have led to fewer studies being included in this review.</p> Conclusions/interpretation <p>Type 2 diabetes prevalence among Indigenous adult populations was markedly higher than the global averages in every decade from 1980 to 2020, with a mean of 73% of populations reporting higher prevalence. These findings underscore the persistent and disproportionate burden of diabetes experienced by many Indigenous communities over several decades. Future work should aim to generate representative data on type 2 diabetes prevalence across global Indigenous populations, investigate factors that contribute to alarmingly high and notably low diabetes prevalence, and support Indigenous-led, culturally safe, Indigenous population-specific health practices to prevent and manage type 2 diabetes and achieve equitable outcomes.</p> Funding <p>There was no funding source for this study.</p> Trial registration <p>PROSPERO registration no. CRD42021258623</p> Graphical Abstract <p></p>