BackgroundDiabetes is a recognized risk factor for dementia, but its impact on dementia burden across sociodemographic groups in Australia is not well characterized.ObjectiveTo compare prevalence of dementia among Australians with and without diabetes and examine variation across key sociodemographic factors.MethodsWe conducted a cross-sectional analysis of the 2021 Australian national census among respondents aged 60-99 years. Prevalence was stratified by education, income, socioeconomic disadvantage, remoteness, and country of birth.ResultsAge- and sex-standardized prevalence of dementia was higher in Australians with diabetes (3.83%) than in those without (3.33%), representing a 15% higher prevalence in the diabetes population. Women with diabetes had a higher prevalence than women without diabetes and men with diabetes. Across all sociodemographic strata, the prevalence of dementia was consistently higher among Australians with diabetes; however, the gap between Australians with and without diabetes widened in certain sociodemographic groups. The largest differences were observed among Australians with no education (6.56% versus 4.78%, 37% higher), those in remote areas (4.37% versus 3.22%, 36% higher) and those born in Vietnam (4.71% versus 3.79%, 24% higher) or China (3.81% versus 2.95%, 29% higher). Differences were also observed for those living in the most socioeconomically disadvantaged areas (4.72% versus 4.29%, 10% higher) and earning <$500/week (4.00% versus 3.47%, 15% higher). After adjusting for age and sex, the prevalence of dementia was 15% higher in the diabetes population, with this elevated risk persisting across sociodemographic strata.ConclusionsDementia is more prevalent among Australians with diabetes as compared with Australians without diabetes, particularly in socioeconomically and culturally disadvantaged populations. Addressing sociodemographic inequities is essential to reduce the burden of diabetes-related dementia in Australia's aging population.