The addition of fillers will vary the mechanical properties of fibre reinforced polymer composites. Experimental studies are carried out to understand the effect of Yttrium powder as filler material in glass-epoxy composites in the research work. The E-glass/epoxy composite plates filled with changing concentrations of Yttrium powder (0% and 5% by weight of epoxy) were prepared initially. As per ASTM 3039 standard, the samples were tested for tensile test and found that the sample with 5% Yttrium was observed with higher ultimate stress and elongation percentage than the sample without Yttrium. Further, the samples were tested for their hardness as per ASTM E92-17 standard, 22.7 ± 1 Hv was observed for the sample with 5% Yttrium and 2.39 ± 0.5 Hv for the sample made without the addition of Yttrium. The significance of the addition of pure Yttrium powder as filler material is proved, and the results on the effect of addition of Yttrium powder as filler are elaborated in this work.