We demonstrated correlations between mechanically bent tensile-strain-induced two-dimensional MoS2 nanosheets (NSs) and their electrochemical activities toward the hydrogen evolution reaction (HER). The tensile-strain-induced MoS2 NSs showed significantly steeper polarization curves and lower Tafel slopes than the strain-free ones, which is consistent with the simple d-band model. Furthermore, the mechanical strain increased the electrochemical activities of all the NSs toward the HER except those loaded with high MoS2 mass. Mechanically bending MoS2 NSs to induce tensile strain enables the production of powerful, efficient electrocatalysis systems for evolving hydrogen.