Nanodiamond is widely used in advanced industrial and biomedical applications due to its unique combination of hardness, chemical stability, and biocompatibility. In industrial settings, it serves as an ultrafine polishing agent for precision optics, semiconductors, and hard disk surfaces, delivering scratch-free finishes. It is also incorporated into lubricants to reduce friction and wear in mechanical systems, enhancing equipment lifespan. In the biomedical field, nanodiamond is used as a carrier for targeted drug delivery, especially in cancer therapy, where it helps improve the solubility and controlled release of chemotherapeutic agents. Its surface can be easily modified to attach drugs, genes, or imaging agents, making it valuable in theranostics—combined therapy and diagnostics. Nanodiamond-based contrast agents are explored in bioimaging due to their fluorescent properties and low toxicity. Additionally, nanodiamond is being investigated in composite materials to enhance strength, thermal conductivity, and wear resistance in polymers and coatings. It also shows promise in quantum sensing and electronic devices due to its nitrogen-vacancy center properties, enabling high-sensitivity magnetic and thermal detection at the nanoscale.