Disclosed herein is a power supply circuit for a gate driver. The power supply circuit for the gate driver includes a negative voltage generator configured to generate a negative voltage by receiving an input voltage, wherein the negative voltage generator includes a tank capacitor configured to be charged by receiving the input voltage through a charge path, a discharge switch configured to form a discharge path when the tank capacitor is discharged, and a negative voltage generation capacitor arranged on the discharge path and configured to generate the negative voltage by storing electric charges discharged from the tank capacitor when the tank capacitor is discharged.