In this study, the mechanical properties of potato starch-based composites containing glycerin and polyvinyl acetate and reinforced with fibers obtained from human hair waste were investigated. The weight percentage of human hair fibers and the glycerin-to-starch weight ratio were selected as the main variables. The samples were produced by hand molding after thermal gelatinization of the matrix and incorporation of the fibers, and were evaluated using tensile and shear tests. Increasing the weight percentage of human hair fibers from 7 to 10% at a constant glycerin-to-starch weight ratio resulted in increased tensile and shear strengths. Increasing the glycerin-to-starch weight ratio reduced both tensile and shear strengths. The sample containing 10 wt% human hair fibers and a 50% glycerin-to-starch weight ratio exhibited an ultimate tensile strength of 5.5 MPa, a shear strength of 19.9 MPa and a total toughness of 1.57 MJ/m³, showing the highest mechanical performance among the investigated samples. For comparison of the reinforcing phase efficiency, a sample reinforced with wool fibers was also produced under the same conditions. The sample reinforced with human hair fibers provided better mechanical performance than the sample reinforced with crimped wool fibers.