The aim was to describe the association between socio-economic inequalities (SEI) and the prevalence/incidence of pharmacologically-treated type 2 diabetes (T2D) in France over the 2010-2020 period. Diabetes cases were identified using a validated algorithm in the French national health data system. Analyses were restricted to adults =45 years to focus on T2D. SEI were measured, each year, via the French Deprivation index (FDep, by population quintiles; Q1: corresponding to the less deprived municipalities) for metropolitan France. The relative risks (RR) of being T2D (prevalence) and developing T2D (incidence) in Q2, Q3, Q4 and Q5 were estimated by sex over the period via Poisson regression. Denominators were the French health consumers (from 24,228,526 in 2010 to 29,772,928 in 2020) for prevalence and the at risk population for incidence. A positive gradient was observed in the RR of T2D prevalence and incidence by FDep quintiles in all years. The influence of SEI (reference Q1) on T2D prevalence increased over the period for men in Q2, Q3, Q4 and Q5, and for women in Q3, Q4 and Q5; and on T2D incidence for men in Q4 and Q5. To conclude, SEI were positively associated with the prevalence/incidence of pharmacologically-treated T2D in metropolitan France. Further, the association increased over last decade for prevalence, and only in most deprived men for incidence.