Abstract There is an emerging epidemic of type 2 diabetes (T2DM) in younger adults. They represent an extreme phenotype: likely to be obese, lead a sedentary lifestyle, have a strong family history of T2DM, be of black or minority ethnic origin, and come from less affluent socioeconomic groups. An accurate diagnosis of T2DM in younger adults, while essential to guide management, can be challenging even for the experienced diabetologist. Comorbidities such as hypertension, nephropathy and hyperlipidaemia are prevalent in this group, and, despite the lack of longitudinal data, they represent a very high risk group, with a need for aggressive management. This focused review of the epidemiology, aetiology, clinical outcomes, comorbidities and management of younger adults with T2DM will provide the non-specialist with up-to-date insight into the UK’s emerging epidemic.