A transfer ratio varying apparatus includes: a steering shaft configured to transmit a steering angle, an actuator connected to the steering shaft and a damper disposed between the input shaft and the steering shaft and configured to absorb vibration caused by the actuator. The actuator includes: a housing, an input shaft configured to integrally rotate with the housing and connected to the steering shaft, a motor including a rotatable shaft, an output shaft configured to transmit an angle to a wheel assembly, and a gear mechanism between the rotatable shaft and the output shaft at the housing, configured to adjust a rotational angle of the rotatable shaft and to output the adjusted rotational angle to the output shaft.