A motor vehicle steering system with steer-by-wire functionality may include an upper steering shaft that is mounted in a steering column and can be connected to a steering wheel in a rotationally fixed manner, a lower steering shaft that is connected to a steering gear for pivoting at least one steerable wheel, a manual torque adjuster that is connected to the upper steering shaft, an actuating drive that is connected to the lower steering shaft, and a coupling that in a closed state couples the steering wheel and the steering gear in a rotationally fixed manner. The actuating drive may be disposed on the steering column.