<p>The research investigates the impact of the incorporation of Syzygium cumini bio-filler on the mechanical properties of untreated Murraya koenigii fiber-reinforced epoxy composites. A hand lay-up was used to produce composites with 0 wt%, 4 wt% and 6 wt% of Syzygium cumini powder. Evaluation of mechanical performance was conducted using tensile, flexural, impact, and hardness tests in accordance with ASTM standards. These findings prove that the mechanical properties are significantly enhanced with the incorporation of 4 wt% bio-filler as compared to the unfilled composite. The increased tensile and flexural strength shows improvement in the transfer of stress between fiber and matrix, whereas the increased impact strength and hardness are indicative of increased capacity to absorb energy and a hard surface. Nonetheless, additional loading of fillers to 6 wt% results in a slight decrease in performance, which can be explained by potential agglomeration and stress concentration effects of the fillers in the matrix. The addition of 4 wt% Syzygium cumini bio-filler results in the highest enhancement in mechanical properties, demonstrating that the material can be used in lightweight structural applications.</p>