A vehicle behavior control apparatus includes a rotary body formed as a part of a power plant installed in a vehicle, and a shaft deflection unit that sets a vehicle behavior target value for obtaining a target vehicle behavior, and deflects a direction of a rotary shaft of the rotary body relative to a vehicle body in accordance with the vehicle behavior target value. Thus, the vehicle behavior can be controlled appropriately by using a pre-existing vehicle constitutional component such as an engine or a motor as the rotary body, and using a gyro moment generated by deflecting the direction of the rotary shaft of the rotary body.