Polycystic ovary syndrome (PCOS) is a heterogeneous familial disorder affecting up to one in five women. The aetiology remains unclear, but available evidence suggests it is a polygenic disorder with epigenetic, developmental, and environmental components. The diagnostic criteria for PCOS are based on reproductive features, and the syndrome is categorized into several phenotypes that can vary by race and ethnicity. Insulin resistance and metabolic dysfunction have a crucial role in the pathogenesis of the syndrome and contribute to many adverse metabolic outcomes that place a substantial burden on the health of women with PCOS across their lifespan. Metabolic abnormalities like those identified in women with PCOS are also present in their female and male first-degree relatives. Overall, more emphasis is required on defining PCOS as a metabolic disorder in addition to a reproductive one. This approach could affect the management and future treatment options for the syndrome. The rationale of the current review is to identify and analyse existing evidence for PCOS as a metabolic, as well as a reproductive, disease.