<p>Ageing is an important risk factor for cancer incidence and augments cancer progression. A shared hallmark of ageing and cancer is metabolic reprogramming, which has been suggested to be not only a cause but also a consequence of ageing. Strikingly, many age-regulated pathways are known to also drive tumour progression, suggesting that metabolic reprogramming connects ageing and tumorigenic processes and shapes whether malignant phenotypes manifest, thrive and evolve. With the rising average age of the world population, understanding how age-related changes in the body influence cancer progression is of paramount importance. In this Perspective, we discuss the metabolic changes that occur with ageing and their potential links with tumour initiation and progression and the development of metastatic disease. Finally, we discuss age-induced metabolic divergences that cause racial disparities and their consequences for the tumorigenic process.</p>