Background: Diabetes is a chronic metabolic disorder that leads to significant damage to vital organs due to prolonged high blood glucose levels. These complications include cardiovascular disease, peripheral neuropathy, retinopathy (eye damage), nephropathy (kidney damage), myopathy, and foot infections. Type 2 diabetes mellitus (T2DM) is the most common form of diabetes, primarily affecting adults when the body becomes resistant to insulin or when insulin production by the pancreas is insufficient. Turmeric (Curcuma longa), a spice widely used around the world, has been traditionally recognized for its numerous health benefits, including antidiabetic, antioxidant, antibacterial, hepatoprotective, and anticancer properties. Among its active compounds, curcumin, a polyphenolic curcuminoid, has garnered significant attention for its potential role in managing diabetes and its complications. Methods: Data for this review were obtained from databases including PubMed, Elsevier, ScienceDirect, and Google Scholar. Search terms utilized included "diabetes," "type 2 diabetes," "diabetic complications," "turmeric," "curcumin," "oxidative stress and curcumin," "curcumin and nephropathy," "curcumin and retinopathy," "curcumin and neuropathy," "curcumin and cardiovascular diseases," "curcumin and cardiomyopathy," “curcumin and pyroptosis,” "curcumin and diabetic foot ulcer," and "curcumin and erectile dysfunction." Results: This review highlights the promising role of curcumin in transforming diabetes treatment and management. The findings demonstrate that curcumin offers protective effects against diabetic complications by modulating key signaling pathways, such as NF-κB, AMPK, MAPK, and AP-1. Its anti-inflammatory properties, inhibition of hepatic gluconeogenesis, and reduction of oxidative stress through antioxidant activity present a strong case for its therapeutic potential in diabetes care. Conclusion: This review provides an in-depth explanation of curcumin's mechanisms of action, detailing its medicinal effects on diabetes-related complications and key outcomes from preclinical and clinical studies supporting its potential benefits. It also outlines future directions for research into curcumin's role in diabetes treatment.