Introduction: -Type 2 Diabetes Mellitus (T2DM) and Gestational Diabetes Mellitus (GDM) are major metabolic disorders contributing substantially to global morbidity and public health burden. Although both conditions share common metabolic and environmental determinants, their epidemiological characteristics and genetic predisposition differ considerably. Understanding these similarities and differences is essential for developing targeted preventive and therapeutic strategies. Objectives The present study aimed to compare the epidemiological characteristics, risk factors, and genetic associations of T2DM and GDM among women in East Godavari district, Andhra Pradesh, India. The study also planned to evaluate the association of TCF7L2 gene Materials and Methods polymorphisms (rs7903146 and rs7901695) with susceptibility to T2DM and GDM and to highlight implications for public health interventions. A case–control study was conducted among 600 human subjects recruited from Rajahmundry, Kakinada, and Rajanagaram in East Godavari district, Andhra Pradesh. The study population comprised 150 T2DM patients, 150 GDM patients, 150 T2DM controls, and 150 GDM controls. Ethical approval was obtained from the Institutional Ethics Committee of Andhra University (IEC No: 2). Detailed bilingual questionnaires (Telugu and English) were administered to collect demographic, socio-economic, clinical, reproductive, dietary, and family history data. Written informed consent was obtained from all participants. Phenotypic screening and molecular analysis were performed to investigate the distribution of TCF7L2 polymorphisms rs7903146 and rs7901695. Genotype and allele frequencies were analysed, and the Hardy Weinberg equilibrium (HWE) was assessed. Results Comparative epidemiological analysis revealed that both T2DM and GDM shared common risk factors such as obesity, co-morbid conditions, and age at menarche. However, T2DM showed stronger associations with increasing age, multiparity, and hysterectomy status, whereas GDM was significantly associated with literacy status, dietary patterns, family history of diabetes, and previous history of GDM. Genetic analysis demonstrated significant differences in genotype and allele frequencies of rs7903146 and rs7901695 between T2DM patients and controls, indicating a strong association between TCF7L2 polymorphisms and T2DM susceptibility. Deviations from Hardy Weinberg equilibrium further supported genetic predisposition in T2DM subjects. In contrast, no statistically significant association was observed between these SNPs and GDM. The absence of significant genetic association in GDM may be attributable to population stratification or limited sample size. Conclusion