A system and a method for estimating a steering torque, may include receiving, in a controller, information including a value of a yaw rate and a value of a lateral acceleration of a vehicle collected in the vehicle in real time; determining and estimating, in the controller, a value of a rack force from the received information and a setting information using a predetermined model formula of estimating the rack force; and generating, in the controller, an estimated value of the steering torque according to an operation of a steering wheel of a driver from the estimated value of the rack force using a predetermined value of a gain.