Introduction – The objective of our study is to estimate the prevalence of self-reported diabetes—i.e., diagnosed diabetes—in the general adult population across four overseas departments and regions (DROM): Guadeloupe, Martinique, French Guiana, and Réunion. In addition, we explore the concept of “mild diabetes,” defined in this study as “early-stage diabetes, but not too severe.” We also describe the characteristics of people with diabetes as well as their care. Methods – The data used come from the 2021 Baromètre de Santé Publique France DROM, a cross-sectional survey based on samples generated by random selection of telephone numbers. More than 6,500 people aged 18 to 85 (1,511 in Guadeloupe, 1,526 in Martinique, 1,478 in French Guiana, and 2,004 in Réunion) were interviewed by telephone about their awareness of diabetes or “mild diabetes,” the duration of the condition, and their respective management. Results – In 2021, the prevalence of known diabetes was 13.6% in Réunion, 12.0% in Guadeloupe, 11.6% in French Guiana, and 11.5% in Martinique. Among those who did not report having diabetes, the proportion of "mild diabetes" was estimated at 4.1% in Martinique, 3.6% in Guadeloupe, 3.4% in Réunion, and 2.5% in French Guiana. Eighty-two percent of people with known diabetes were receiving pharmacological treatment in Réunion, while 90% were in French Guiana, 92% in Martinique, and 93% in Guadeloupe. Among people with diabetes not receiving pharmacological treatment residing in the four DROMs, 42% followed a diet, 33% engaged in physical activity, 14% monitored their blood glucose levels, and 26% used herbal remedies. Finally, 44% of people with diabetes not receiving pharmacological treatment reported using no recommended management measures (35% used no measures at all and 9% used only herbal remedies). Conclusion – Our study reports a high prevalence of known diabetes in the DROMs, including a significant proportion of cases not treated with medication, among whom more than four in ten do not benefit from any lifestyle or dietary measures, regardless of the DROM. Furthermore, we report a high frequency of cases of "mild diabetes," which represents a potential barrier to appropriate management.