An electric power steering system includes an electric motor, a rotational angle detection unit, a current detection circuit, a steering torque detection unit, a target torque setting unit, a current command value setting unit, and a current control unit. The target torque setting unit includes a basic target torque setting unit, a first compensation value computation unit, a second compensation value computation unit, and a correction unit. The basic target torque setting unit sets basic target torque for the electric motor. The first compensation value computation unit sets a first compensation value based on steering torque. The second compensation value computation unit computes a second compensation value which is an estimated value of disturbance torque other than the steering torque. The correction unit corrects the basic target torque.