Type 2 diabetes (T2D) is increasing in the United States, currently affecting 11.3% of the nation. The Developmental Origins of Health and Disease Hypothesis suggests that environmental stresses in utero and in early stages of life, such as preterm birth (age), can lead to development of adulthood diseases, including T2D. However, research on the association between preterm birth and T2D is sparse and predominantly based on European ancestry populations. We examined this association in postmenopausal women (N = 85,356) from the Women’s Health Initiative, a nationwide prospective cohort. Logistic regression models were used to examine the association between self-reported preterm birth and T2D status, adjusting for demographic and lifestyle covariates. Preterm birth was significantly and positively associated with odds of T2D at baseline (unadjusted: OR=1.51, 95% CI 1.24, 1.83; P