Diabetes stigma is the social burden of living with diabetes. People with diabetes may experience or perceive an adverse social judgment, prejudice, or stereotype about living with diabetes at work, school, in healthcare settings, popular culture, or relationships. This review describes the methods that have been used to assess diabetes stigma, and explores the prevalence of diabetes stigma, associated sociodemographic and socioeconomic factors, cultural factors, and how diabetes stigma is associated with clinical outcomes, including HbA1c levels, diabetic ketoacidosis, severe hypoglycemia, and chronic complications, in addition to psychosocial complications in youth, adolescents, and adults with type 1 diabetes (T1D) and type 2 diabetes (T2D). The prevalence of diabetes stigma has been reported as high as 78% in adults with T1D, 70% in adults with T2D, 98% in youth and adolescents with T1D, and is unknown in youth and adolescents with T2D. Diabetes stigma has been associated with lower psychosocial functioning, decreased self-care behaviors, higher HbA1c levels, and higher frequency of diabetes complications in adults with T1D and T2D. In adolescents and young adults with T1D, diabetes stigma is associated with lower psychosocial functioning, higher HbA1c levels, and higher frequency of diabetic ketoacidosis and severe hypoglycemia episodes in addition to chronic complications. In youth and adolescents with T2D, one study demonstrated an association of diabetes stigma with lower psychosocial functioning, higher HbA1c levels, and presence of retinopathy. Gaps exist in our understanding of the mechanisms of diabetes stigma, particularly in youth and adolescents with T2D.