The increasing global prevalence of diabetes mellitus presents a significant challenge to healthcare systems today. Although diabetic retinopathy, nephropathy and neuropathy are well-established complications of diabetes, there is a paucity of research examining the impact of dysglycaemia on the olfactory system. Olfaction is an important sense, playing a role in the safety, nutrition and quality of life of an individual, but its importance is often overlooked when compared with the other senses. As a result, olfactory dysfunction is often underdiagnosed. The present review article aims to present and discuss the available evidence on the relationship between diabetes and olfaction. It also explores the associations between olfactory dysfunction and diabetes complications that could explain the underlying pathogenesis. Finally, it summarizes the putative pathological mechanisms underlying olfactory dysfunction in diabetes that require further investigation.