Diabetes mellitus is a chronic condition which disrupts bone homeostasis leading to impaired healing and profound complications in ankle fractures. Hyperglycaemia and chronic inflammation cause increased generation of advanced glycation end products and reactive oxygen species which ultimately drive osteoclastogenesis and increase bone resorption. Together with a lack of insulin signalling, these mechanisms compromise bone metabolism and increase the risk of complications in fracture healing. Diabetes is associated with comorbidities such as vasculopathy and neuropathy which further contribute to the risk of complications. The complications identified in diabetic patients with ankle fractures include non-union, malunion, infection, amputation, and mortality. Thus, careful consideration is needed when deciding between surgical and conservative treatment. This narrative review provides a synthesis of the literature covering the impact of diabetes on ankle fractures, considering their high prevalence in the UK.