Objective: The objective was to describe the impact of socioeconomic inequalities (SEI) on COVID-19 mortality among people living with medically managed diabetes (MTD) during the two waves of the pandemic (Wave 1: March–May; Wave 2: September–December) in 2020 in mainland France. Methods: People with MD were identified using a validated algorithm¹ in the National Health Data System. COVID-19 mortality for the year 2020 was identified among the medical causes of death for individuals alive as of January 1, 2020. Social deprivation indices (SDIs) were measured using the social deprivation index² (FDep, by population quintiles; Q1: most advantaged municipalities). Age-standardized mortality rates (ASMRs) (2013 European standard population) per 100,000 person-years are presented with their 95% confidence intervals [95% CI]. Results: In V1, the highest age-standardized mortality rate (ASMR) was observed among DT men residing in the most advantaged municipalities (Q1: 99.4 [87.1–111.7]). Then, the TMstd decreased through Q3 before increasing through Q5 to 77.2 [71.2–83.2]. This same trend was observed, though less markedly, among DT women (Q1: 64.3 [55.6–73.1]; Q5: 49.1[44.4–53.8]) and among non-DT men and women. In V2, the TMstd remained stable from Q1 to Q4, at approximately 80 per 100,000, and was significantly higher in Q5: 100.0[92.1–107.9] among DT men. Among women with disabilities, no difference was observed based on the level of disability: Q1: 57.0 [48.5–65.5] and Q5: 57.0 [51.9–62.0], whereas an increasing gradient was observed among men (Q1: 48.2 [46.1–50.3]; Q5: 57.7 [55.5–59.9]) and non-DT women (24.5 [23.4–25.7] and 32.5 [31.3–33.8]). Discussion: These initial descriptive results show that the impact of ISE on COVID-19 mortality appears to differ between the two epidemic waves of 2020. They raise questions about the impact of public health measures on social health inequalities.