Epithelial ovarian cancer (EOC) is one of the most common causes of cancer-related deaths among women and is associated with age and age-related diseases. With increasing evidence of risks associated with metabolic inflammatory conditions, such as obesity and type 2 diabetes mellitus (T2DM), it is important to understand the complex pathophysiological mechanisms underlying cancer progression and metastasis. Age-related conditions can lead to both genotypic and phenotypic immune function alterations, such as induction of senescence, which can contribute to disease progression. Immune senescence is a common phenomenon in the ageing population, which is now known to play a role in multiple diseases, often detrimentally. EOC progression and metastasis, with the highest rates in the 75–79 age group in women, have been shown to be influenced by immune cells within the “milky spots” or immune clusters of the omentum. As T2DM has been reported to cause T cell senescence in both prediabetic and diabetic patients, there is a possibility that poor prognosis in EOC patients with T2DM is partly due to the accumulation of senescent T cells in the omentum. In this review, we explore this hypothesis with recent findings, potential therapeutic approaches, and future directions.