Abstract: The relationship between the course of type 2 diabetes mellitus (T2DM) and the risk of the female reproductive malignancies is complex and multifaceted. Large population cohort studies have indicated a negative association between the T2DM duration and the incidence of breast cancer and endometrial cancer. Furthermore, a large number of studies have shown that the risk of breast and endometrial cancer within a short time after T2DM diagnosis is highest, and the risk remains significantly higher in patients with longer duration of diabetes than in the non-diabetic population; this suggests that causal reverse bias and potential detection bias may play a role, but T2DM remains an important risk factor for the occurrence of breast and endometrial cancer. Research on the association between diabetes and the incidence of cervical and ovarian cancer is limited, and results vary by region. Future epidemiological studies should focus on larger prospective studies with longer follow-up to further investigate the association between diabetes and cervical and ovarian cancer. There is also a need to explore into the biological mechanisms linking diabetes and female reproductive cancers in order to develop effective cancer prevention and early intervention strategies.