Background <p>Wearable technologies are increasingly used for health and lifestyle monitoring, yet emerging devices such as smart rings have not been comprehensively evaluated for their potential benefits in diabetes care. We conducted a scoping review to summarize scientific evidence on the use of smart rings among people with diabetes.</p> Methods <p>We searched Embase, Global Health, Medline, Scopus, and Web of Science on November 10th, 2025, to identify original studies involving individuals with type 1, type 2, or gestational diabetes who used smart rings, either alone or alongside other wearable devices. We synthesized the findings qualitatively in a narrative format, focusing on reported health and behavioral outcomes.</p> Results <p>Of 122 records identified, three studies met inclusion criteria. All were observational, conducted in high-income settings, and focused on adults with type 2 diabetes. Sample sizes ranged from 14 to 262 participants. One study evaluated smart rings within an enhanced diabetes-care model and reported significant short- and long-term improvements in several cardiometabolic biomarkers such as HbA1c and lipids. The other two studies tested prototype rings for glucose prediction or peripheral hemodynamic assessment using photoplethysmography.</p> Conclusions <p>Current evidence on smart ring use in people with diabetes is limited. The evidence primarily shows the feasibility of smart rings for monitoring health markers. Clinical effectiveness, long-term health outcomes, and patient-important outcomes remain unknown due to the dearth of randomized experiments and extended follow-ups.</p>