The vehicle behavior control device comprises an engine control part operable, when an steering speed is greater than a predetermined threshold, and both of a steering wheel angle of a vehicle and the steering speed are increasing, to reduce an output torque of a multi-cylinder internal combustion engine along with an increase in the steering speed, and when the steering speed is equal to or less than the threshold, to stop the reduction of the output torque, and a threshold setting part operable, when the operation mode of the engine is the all-cylinder operation, to set the threshold to a first threshold TS1, and, when the operation mode of the engine is the reduced-cylinder operation, to set the threshold to a second threshold TS2 which is less than the first threshold TS1.