<p>This study examines the impact of different silica filler loading levels on the mechanical, dynamic mechanical, and water absorption properties of PLA/ABS/kenaf hybrid composites with the aim of optimizing the best formulation for multifunctional performance enhancement. Five composite formulations S1 to S5 were prepared with 5 wt%, 10 wt%, 15 wt%, 20 wt%, and 30 wt% silica loading, respectively, and a constant kenaf fiber loading. The work systematically examines the impact of incremental silica loading on static mechanical properties such as tensile, flexural, compressive, and impact strengths and dynamic mechanical properties such as storage modulus, loss modulus, and damping factor. Water absorption performance was also measured under different exposure conditions such as immersion in distilled water, NaCl solution, and a NaCl–distilled water mixture to represent varied environmental interactions. The aim is to identify the optimum silica concentration with the best combination of stiffness, energy dissipation capacity, interfacial bonding, and moisture resistance. The findings are expected to inform the design of sustainable composite materials with enhanced functional properties for structural, automotive, and packaging applications where durability, lightweight design, and environmental performance are paramount.</p>