Immunometabolism, encompassing metabolic processes within the immune system, plays a pivotal role in modulating the development, activity, and function of immune cells. Oxidative stress, resulting from an imbalance between pro-oxidants and antioxidants, is a critical factor in the pathogenesis of various diseases, including cancer and aging. This review synthesizes current knowledge on the interplay between immunometabolism and oxidative stress, highlighting their mechanisms in cancer progression and the aging process. We discuss how metabolic reprogramming in our body can influence immune cell function and promoting ageing and cancer development. Additionally, we examine the impact of aging on immune metabolism, leading to a decline in immune function and a predisposition to chronic diseases. The review also explores the potential of traditional Chinese medicine in targeting oxidative stress to delay aging and combat cancer, underscoring the need for further research to elucidate the molecular mechanisms underlying these effects. Our findings suggest that interventions targeting immunometabolism and oxidative stress could offer novel therapeutic avenues for cancer and aging-related diseases.