A vehicle steering system in which a steering member and a steered wheel are not mechanical coupled to each other includes a rotation angle restriction mechanism that restricts a rotation angle of the steering member within a restricted angular range. In a normal mode, drive control on a steered system actuator is executed on the basis of a steering angle detected by a steering angle sensor. In a failure mode for a situation in which there is a malfunction in the steering angle sensor, drive control on the steered system actuator is executed on the basis of a steering direction detected by a steering direction detection sensor. The steering direction detection sensors detect the steering direction on the basis of at which one of a pair of terminal ends of the restricted angular range, the rotation angle restriction mechanism is restricting the rotation angle of the steering member.