• Eco and Biocomposite based on halloysite, kojic acid, and ionic liquid for coatings • Extensive material characterization: IR, TGA, XPS, Zeta potential, TEM, and EDX • Dual-function coating offers antibacterial and anticorrosive performance • Eco-friendly solution for microbial contamination and metal corrosion challenges In this study, we present a novel multifunctional filler for protective coatings, highlighting its straightforward and rapid synthesis. This composite is based on halloysite nanotubes (HNTs), a naturally occurring clay mineral, covalently functionalized with kojic acid (K), a naturally occurring chelating agent. This unique combination offers powerful antibacterial and anticorrosive properties. The kojic acid-functionalized halloysite nanotubes (HNT-K) were then loaded with an ionic liquid (IL), leveraging synergistic interactions to effectively inhibit iron oxidation and provide robust surface protection. The composite underwent comprehensive characterization through Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Transmission electron microscopy (TEM), and Linear Polarization Resistance (LPR) analyses, which unequivocally confirmed successful functionalization and loading, along with a significant improvement in both corrosion resistance and antimicrobial efficacy. The composite demonstrated remarkable enhancements in the corrosion resistance of DD11 steel, notably reducing the corrosion rate from 0.34 mm/year to an impressive 0.12 mm/year. Furthermore, the material exhibited potent antimicrobial activity, especially against P. aeruginosa and C. albicans (69.23 and 84.61) as % of inhibition respectively, underscoring its immense potential for eco-friendly and sustainable applications in protective coatings. The utilization of halloysite and kojic acid, both sourced from nature, emphasizes the inherent sustainability of our approach, providing a truly green solution for surface protection with a powerful dual action: anticorrosive and antibacterial. We have thus successfully developed a novel, entirely natural-origin filler for paints offering this extraordinary dual action, all achievable through a fast and straightforward synthetic route.