In this work, we present the investigation of the combination of gate recess and tri-gate structures to achieve high performance normally-off GaN-on-Si MOSFETs with high positive threshold voltage ( VTH ), low specific on resistance ( RON,SP ) and high output current ( ImaxD ). The excellent channel control capability offered by tri-gate structure led to a reduced OFF-state leakage current ( IOFF ), higher ON/OFF ratio, smaller subthreshold slope ( SS ) compared to similar planar and recessed-gate devices. With gate to drain length ( LGD ) of 20 μm , a hard VBR of 2050 V were achieved, along with a low RON,SP of 2.42 mΩ⋅cm2 , which corresponds to a state-of-the-art figure of merit (FOM) of 1.73 GW/cm 2 . These results unveil the extraordinary prospects of tri-gate technology for future power electronics applications.