<p>Carbon-based nanomaterials, with dimensions comparable to biomolecules, offer unique advantages in biomedical applications due to their ability to penetrate cells, interact with tissue microenvironments, and target-specific biomolecules. These materials possess excellent electrical and optical properties, large surface areas, good biocompatibility, low toxicity, and tunable surface functionalities. Representative examples such as graphene, carbon nanotubes (CNTs), carbon quantum dots (CQDs), fullerenes (C₆₀), and nanodiamonds (NDs) have demonstrated significant bioactivity and therapeutic potential. In recent years, these carbon nanomaterials have garnered attention in diabetes management due to their versatility and therapeutic capabilities. They are increasingly used to enhance the sensitivity and stability of glucose sensors, enabling the development of miniaturized, wearable devices for glucose monitoring. Moreover, their modifiable surfaces and drug-loading capacities facilitate targeted delivery and controlled release, which improves therapeutic precision while minimizing side effects. Beyond glucose sensing and drug delivery, specific carbon nanomaterials also exhibit intrinsic antioxidant, anti-inflammatory, and antimicrobial effects, which can aid in treating diabetes-related complications, such as diabetic foot ulcers and chronic wounds. Additionally, they promote tissue regeneration and angiogenesis, which are crucial for effective wound healing. Despite these promising applications, a comprehensive review of their role in diabetes management remains limited. This review aims to summarize the latest advancements in glucose sensing, drug delivery, antioxidation, wound healing, and inflammation control using carbon-based nanomaterials, while highlighting current challenges and outlining future research directions for translating these technologies into clinical applications in diabetes nanomedicine.</p>