Gestational diabetes mellitus (GDM) could increase the risks of type 2 diabetes mellitus (T2DM) and cardiovascular disease. However, evidence on its association with cardiometabolic multimorbidity (CMM) was limited. This study aimed to evaluate the association between GDM and the prevalence, incidence, patterns, and progression of CMM; and the role of body mass index (BMI) in such association.