Heterogeneous integration of III–V compound semiconductors to Si substrates is regarded as a necessary step for advancing high-speed electronics and hybrid optoelectronic systems for data processing and communications, and is extensively being pursued by the semiconductor industry. Here, an innovative fab-compatible, hybrid integration process of III–V materials to Si, namely InGaAs thin films to insulator-on-Si, is reported, and the first III–V FinFET devices on Si are demonstrated. Transfer of crystalline InGaAs layers with high quality to SiO2/Si is accomplished by the formation of a robust interfacial nickel-silicide (NiSi) bonding interface, marking the first report for using silicides in III–V hybrid integration technology. The performance of optimally fabricated InGaAs FinFETs on insulator on Si is systematically investigated for a broad range of channel lengths and Fin perimeters with excellent switching characteristics. This demonstrates a viable approach to large-scale hybrid integration of active III-V devices to mainstream Si CMOS technology, enabling low-power electronic and fully-integrated optoelectronic applications.