Quercetin (Qu), a naturally occurring flavonoid with potent antioxidant, anti-inflammatory, and anticancer properties, faces clinical limitations due to poor solubility, low stability, and suboptimal bioavailability. This review comprehensively explores nano-quercetin (nano-Qu) formulations as a transformative solution, focusing on material design, synthesis strategies, and biomedical applications. A comprehensive review of diverse nanocarriers, including lipid-based, inorganic, polymeric, and composite nanoparticles, is presented to systematically evaluate their potential in improving solubility, stability, and targeted drug delivery of Qu. Advanced synthesis techniques such as chemical conjugation, self-assembly, and physical encapsulation are evaluated for optimizing drug loading and controlled release. Preclinical studies highlight nano-Qu's efficacy in cancer therapy, inflammatory disorders, metabolic diseases, and tissue regeneration, attributed to improved pharmacokinetics and target-specific mechanisms. Despite promising advancements, challenges in biocompatibility, long-term toxicity, and scalable production require further investigation. This work underscores the potential of nanotechnology to unlock Qu's therapeutic versatility.