We report the first demonstration of strained In<sub>0.53</sub>Ga<sub>0.47</sub>As-on-insulator (-OI) MOSFETs on Si substrates using the direct wafer bonding (DWB) technique. 1.7 % highly-strained In<sub>0.53</sub>Ga<sub>0.47</sub>As-OI structures were successfully fabricated on Si by DWB. Strained In<sub>0.53</sub>Ga<sub>0.47</sub>As-OI MOSFETs with Ni-InGaAs metal S/D have successfully operated, for the first time. MOSFETs with 1.7 % tensile strain exhibits 1.65 × effective mobility (μ<sub>eff</sub>) enhancement against InGaAs MOSFET without strain with maintaining high I<sub>on</sub>/I<sub>off</sub> ratio of ~10<sup>5</sup>. It is revealed from Hall measurements that the μ<sub>eff</sub> enhancement is attributed to the increase in mobile free electron concentration due to the lowering in the conduction band edge induced by tensile strain.