Diabetes is a common, chronic, and costly condition that currently affects millions of individuals in the United States and worldwide with even greater numbers at high risk for developing the disease. Dramatic increases in diagnosed diabetes are projected for the decades to come meaning that most people will be affected by diabetes; either personally or through a family member. This article introduces the special issue of the American Psychologist focused on diabetes by providing an overview of the scope of diabetes and the importance of psychologists for improving disease management and quality of life. This includes an overview of the contributions of the behavioral and social sciences toward improved diabetes prevention and treatment. Finally, the article will point to opportunities for psychologists to close the gaps in the research, develop practice competencies, and increase training opportunities to meet the challenges of diabetes today and in the future.