The mechanical properties of Sb-doped Mg2Si were measured by various mechanical methods, and the effects of four incorporated metallic binders (Ni, Cu, Zn, and Al) on the mechanical properties were investigated. The measured Young's modulus, bending strength, Vickers hardness, and fracture toughness of Mg2Si without binders were 105GPa, 57 MPa, 700, and 1.2MPam1/2, respectively. These values, except for Vickers hardness, were improved by the addition of the metallic binders. Moreover, the thermoelectric performance of Mg2Si was also slightly improved by the incorporation of the metallic binders. These results suggest that the addition of a metallic binder to Mg2Si is effective in improving its mechanical properties, in addition to improving its thermoelectric property and sinterability.