A vehicular steering system can suppress, even upon a change in a neutral position of a steering wheel, a right and left difference in the behavior of a vehicle by keeping neutral positions of steerable road wheels from the start of control. The system includes a steering mechanism that steers the steerable road wheels of the vehicle through the steering wheel and an auxiliary steering angle superposition mechanism. A steered angle of the steerable road wheels is detected as an absolute angle. The auxiliary steering angle superposition mechanism is controlled by a target auxiliary steering angle. An activation angle setting section sets, at the start of control, the initial values of a steering wheel angle and an auxiliary steering angle as an activation steering wheel angle and an activation auxiliary steering angle by the steered angle and a transmission characteristic between the steering wheel angle and the steered angle.