India’s growing energy demand has led to extensive open-cast coal mining, resulting in the accumulation of large volumes of overburden (OB) materials. Managing these OB dumps poses significant challenges due to slope instability and spatial constraints, particularly in mines with high stripping ratios. This study evaluates the effectiveness of an indigenously developed nanocomposite-coated jute geotextile (JGT) as a sustainable reinforcement solution for enhancing OB dump slope stability. The composite coating, comprising polymethyl methacrylate, polystyrene, and nano fly ash, significantly improved the tensile strength of JGT by 55.7% in machine direction and 51.0 % in cross-machine direction without compromising its porosity. Long-term durability assessments demonstrated a 91.2 % retention of tensile strength for the coated JGT after 6 months of submergence in low-pH water, whereas untreated JGT underwent complete degradation. Geotechnical centrifuge modeling showed substantial reductions in settlement, 88.90 % at the crest and 95.28 % along the slope face under reinforced conditions. Numerical simulations using three-dimensional limit equilibrium analysis indicated a 9.28 % increase in the factor of safety, yielding a 24.05 % increase in volumetric capacity within the same land footprint. A comparative carbon footprint analysis highlighted the environmental benefits of the coated JGT, with a net carbon dioxide (CO₂) absorption of 3.654 kgCO₂/kg, in contrast to emissions of 2.7 kgCO₂/kg for synthetic geotextiles. The successful mass production of the developed JGT further supports its scalability and cost-effectiveness. This study establishes nanocomposite-coated JGT as a technically robust, durable, and eco-friendly alternative to synthetic geotextiles for OB dump slope stabilization in coal mining operations.