Diabetes mellitus is a chronic metabolic disorder characterized by elevated blood glucose levels resulting from impaired insulin secretion, insulin action, or both. The global prevalence of diabetes has increased significantly, creating an urgent need for effective and safe therapeutic strategies. Biotechnology has played a major role in transforming diabetes management, particularly through the development of recombinant therapeutics such as human insulin, insulin analogues, and recombinant proteins that improve glycemic control. Recombinant DNA technology, protein engineering, gene therapy, and stem cell research have contributed to advances in diabetes treatment by improving drug efficacy, safety, and delivery. Modern biotechnological approaches also focus on developing long-acting insulin, glucose-responsive insulin systems, and regenerative therapies aimed at restoring pancreatic β-cell function. This chapter discusses the role of recombinant therapeutics and biotechnology in diabetes treatment, highlighting recent developments and future prospects in this rapidly evolving field