<p>The growing concern for environmentally friendly and sustainable materials has encouraged the development of natural fiber-based composites reinforced with biodegradable fillers. In this study, jute fiber was combined with coconut-leaf midrib and eggshell powders to fabricate environmentally sustainable epoxy composites. The novelty of this work lies in the combined use of agricultural and bio-waste fillers with jute fiber to develop cost-effective, environmentally friendly hybrid composites with improved mechanical performance. The fillers, processed to particle sizes below 75 µm, were incorporated at 0.5%, 1%, and 2% weight ratios. The hand layup method was used to fabricate the composites, and tensile, flexural, impact, and water absorption characteristics were evaluated in accordance with ASTM standards. Results revealed significant improvements in mechanical performance with filler addition. The 1% coconut-leaf-midrib composite showed a 20% increase in tensile strength and a 30.8% rise in tensile modulus compared to the base sample. Similarly, the 2% eggshell filler achieved a 26.7% increase in tensile strength, a 42.6% higher tensile modulus, and a 50.9% increase in impact strength. Flexural strength improved by up to 28.7%, while the flexural modulus increased by up to 49% for 2% eggshell filler. Both fillers reduced water absorption by nearly 5%, indicating lower porosity and improved moisture resistance. SEM analysis confirmed enhanced interfacial bonding and reduced void formation in filler-reinforced composites. These eco-friendly composites are promising for lightweight structural, automotive interior, packaging, and sustainable engineering applications.</p>