Fabricating Janus nanoparticle−functionalized fabrics with UV protection, strength enhancement, self-cleaning properties, and wash durability, with a biocompatible nature, is crucial in modern functional fabrics engineering. Particularly, tailoring multifunctional nanoparticles capable of exhibiting several distinct properties, utilizing low-cost raw materials, and adhering to green chemistry principles is pivotal. A fabrication strategy for developing multifunctional reactive Janus nanoparticles, utilizing waste-derived natural polyphenol (quercetin-3-glucuronide, myricetin-3galactoside, gossypin, phlorizin, kaempferol, myricetin-3-arabinoside)−integrated zinc-silica core−shell Janus nanoparticles with UV protection, strength enhancement, and self-cleaning properties, is proposed. Polyphenols were utilized as sustainable precursors for synthesizing zinc-polyphenol complexes, which were then encapsulated within a silica shell to form a core−shell structure. Furthermore, Janus particles were created by introducing a bifunctional layer with half amine/carboxylic acid and half methyl terminals, imparting reactive hydrophilic and hydrophobic properties. Janus-coated textiles and leather exhibited significant attenuation of harmful UV radiation, with water contact angle measurements confirming improved water repellency. The coexistence of natural phenols and bifunctional groups within a material bolstered textile strength, fostering superior adhesion and markedly enhancing wash durability. This eco-friendly approach, utilizing waste-derived materials, presents a promising solution for sustainable textile engineering with enhanced performance in UV protection and water resistance, thereby contributing to the advancement of green nanotechnology in textile applications.