Cell Communication and Signaling — The exponential growth of immunometabolism-related studies in the last 10 years has made it very clear that metabolism is a key player in the effector functions of immune cells. Such is the case in cells with lymphoid origin, as CD4 + and CD8 + T cells undergo a series of metabolic reprogramming steps during their differentiation process, which is associated with a change in their effector characteristics. Only recently have factors such as biological aging and cellular senescence been examined in relation to memory T-cell generation and the metabolic reprogramming that accompanies their differentiation. In this review, we examine the emerging roles of cellular senescence and biological aging in shaping T-cell metabolism and immune function, and how these changes in the T-cell landscape contribute to disease onset. We then discuss recent studies on T-cell metabolic reprogramming to highlight how understanding the impact of senescence on T-cell metabolism may reveal new therapeutic opportunities.