Diabetes mellitus is one of the leading causes of morbidity and mortality worldwide. Type 2 diabetes mellitus is the most prevalent type of diabetes mellitus, and it is associated with both hereditary and lifestyle risk factors. South Africa is not exempt from this pandemic; hence, this paper aims to assess the prevalence and determinants of household self-reported diabetes mellitus in Gauteng, South Africa. Data were sourced from the Gauteng City-Region Observatory (GCRO) quality of life survey (2020/2021). Bivariate and multivariate logistic regressions were applied. The prevalence of household self-reported diabetes mellitus in Gauteng was 11.1%. The ‘other population’ group (which included Whites, Coloureds and Indians), as well as older respondents, higher household monthly food expenditure, poor self-perceived health status and household self-reported hypertension were factors that increased the odds of household self-reported diabetes mellitus. Only informal housing decreased the odds of household self-reported diabetes mellitus. Screening of diabetes mellitus among those with poor living conditions, no medical aid and lack of access to healthcare facilities such as Gauteng township and informal settlement residents should be intensified. This secondary disease prevention intervention is crucial, as it will enhance the appropriate referrals and timeous chronic treatment for those with diabetes mellitus.