<p><?tk 2?>This study aimed to valorize <i>Morinda citrifolia</i> leaves, abundantly available in temple solid waste, by converting them into activated carbon (AC) for use as a functional filler in biodegradable cellulose-based bioplastics. The leaves underwent chemical activation to produce porous AC, which was incorporated at varying concentrations into bioplastics prepared via casting and molding. Characterization using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and UV–Vis spectrophotometry, and Raman spectroscopy confirmed the structural integrity and partial graphitization of the AC, with an I_D/I_G ratio of approximately 1:1. Mechanical analysis showed tensile strengths ranging from 12.8 to 17.2 MPa and elongation at break between 16.9% and 32.5%, indicating improved strength and flexibility due to AC reinforcement. Soil burial degradation tests revealed 97% mass loss after 50 days, confirming excellent biodegradability. Additionally, the AC demonstrated superior photocatalytic activity, achieving near-complete degradation of methyl orange dye within 50 minutes under visible light, outperforming other biomass-derived photo-catalysts. Despite increasing interest in AC-reinforced bioplastics, most existing studies have utilized conventional agricultural residues, with little focus on temple-derived organic wastes or the potential of <i>M. citrifolia</i> leaves as an activated carbon precursor. This gap limits understanding of how such unconventional biomass sources can enhance both material performance and environmental sustainability. These results highlight the dual potential of <i>M. citrifolia</i>-derived activated carbon for enhancing bioplastic performance and serving as an efficient material for environmental remediation. This approach presents a sustainable solution for converting religious plant waste into high-value materials for packaging and wastewater treatment applications.</p>