The demand for sustainable materials has led to the interest in natural fiber composites as well as addressing the environmental concern created by agricultural industries which are palm oil and poultry industries. By leveraging the abundant biomass waste from local palm oil and poultry industries, this research emphasizes the optimization of epoxy hybrid composites reinforced with palm oil empty fruit bunch (EFB) and chicken feathers (CF). The EFBCF composite were studied using various combinations of particle sizes (0.1–2.0 mm), EFB contents (17, 18, and 19%), and CF contents (1, 2, and 3%). The Taguchi method is utilized in determining optimal parameters to improve the composite's properties. The key findings include particle size of 1.0 mm, 17% EFB, and 1% CF are the optimal compositions for tensile strength (as per ASTM D638) where adding 1–2% CF improved tensile performance while 3% CF weakened it. Meanwhile, the optimal combination for reducing water absorption (4.25%) and thickness swelling (2.94%) was achieved using a combination of particle size of 0.1–1.0 mm, 17% EFB, and 3% CF. The optimal hardness was achieved with a particle size of 1.0 mm, 17% EFB, and 3% CF. The study recommends the adoption of the identified optimal parameters and encourages further research to explore broader applications and optimize the composite's properties to maximize environmental benefits.