The immunoproteasome represents a specialized isoform of the proteasome that is integral to the processes of antigen presentation and protein degradation. While it is primarily expressed in hematopoietic cells, its expression can also be induced in non-hematopoietic cells in response to various inflammatory stimuli. Recent research has highlighted the role of the immunoproteasome in modulating islet β-cell apoptosis and glycolipid metabolism, both of which are critical mechanisms in the pathogenesis of diabetes. Furthermore, the immunoproteasome has been demonstrated to play a significant role in the development of diabetic complications through the activation of various downstream cytokines. Investigating how the immunoproteasome is activated and involved in the pathophysiological processes of diabetes and its complications may provide innovative and promising approaches for diabetes treatment. This review aims to present a comprehensive summary of current research on the role of immunoproteasome in diabetes and its associated complications, ultimately identifying novel strategies for diabetes management and therapy.