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.