Wound healing can often be delayed due to non-favourable physiological conditions. Current treatment strategies have many limitations, and the development of novel therapeutic patches is urgently required. Herein, we have developed a hydrogel-based wound healing patch containing quercetin nanocrystals to enhance quercetin solubility, leading to sustained release and improved bioactivity. Due to the anti-oxidant properties of quercetin, a sustained release of the drug is highly beneficial for the rapid repair of wounds by reducing oxidative stress. Quercetin nanocrystals with a size of 600-800 nm were synthesized that demonstrated sustained release of quercetin when fabricated in a hydrogel patch. This has been utilized for in vivo wound repair in rat and mouse models of skin wounds. Overall, our study demonstrates the usability of a novel therapeutic hydrogel patch containing phytochemical-based nanocrystals for rapid wound healing applications.