An active roll control system that may be adapted to actively control roll stiffness of a vehicle by adjusting a mounting position of a stabilizer link connecting a suspension arm with a stabilizer bar of the vehicle on the suspension arm according to a driving condition of vehicle may include a driving unit which including a housing connected with a side of the suspension arm, a rail plate disposed within the housing, and a connector movable along the rail plate, and a stabilizer link of which one end may be connected with an end of the stabilizer bar and the other end may be connected with the connector through a first joint.