Oral health is an integral part of systemic health and plays a significant role in maintenance of general health status. Several factors affect oral health including metabolic disorders such as Diabetes Mellitus. Diabetes Mellitus has become a global epidemic and presents many complications usually proportional to the degree and duration of hyperglycemia. The purpose of this review is to highlight various studies concerning Diabetes Mellitus and its potential effects on oral health. This article aims to review and increase the awareness of oral manifestations and complications of Diabetes Mellitus.