A parking support system comprising: a parking path planning unit configured to plan a trajectory of each unit path when moving a vehicle to a target parking position by repeating a movement of the unit path including one forward movement and one backward movement in succession and to calculate a vehicle control signal that causes the vehicle to move along the trajectory such that a steering angle of the vehicle is substantially 0 degrees at an arrival position of each of the forward movement and the backward movement; and an entry detector configured to detect entry of the unit path into an entry prohibited area, wherein the parking path planning unit is configured to change the trajectory of the unit path to a trajectory for stopping immediately before entering the entry prohibited area and to change the vehicle control signal such that the steering angle of the vehicle at a stop position immediately before the entry prohibited area in the changed unit path is substantially 0 degrees, when the entry detector has detected the entry into the entry prohibited area, and wherein the parking path planning unit is configured to calculate the unit path and the vehicle control signal on the basis of a performance value that is able to be output by an actuator of the vehicle at a time of automatic driving of the vehicle, characterized in that the parking path planning unit is configured to calculate a plurality of candidate unit paths in cases where the vehicle is moved within a range of upper and lower limit values of the performance value that is able to be output by the actuator of the vehicle at the time of automatic driving of the vehicle and to select a unit path which has the shortest distance from an arrival position of the unit path to the target parking position from the plurality of unit paths. a parking path planning unit configured to plan a trajectory of each unit path when moving a vehicle to a target parking position by repeating a movement of the unit path including one forward movement and one backward movement in succession and to calculate a vehicle control signal that causes the vehicle to move along the trajectory such that a steering angle of the vehicle is substantially 0 degrees at an arrival position of each of the forward movement and the backward movement; and an entry detector configured to detect entry of the unit path into an entry prohibited area, wherein the parking path planning unit is configured to change the trajectory of the unit path to a trajectory for stopping immediately before entering the entry prohibited area and to change the vehicle control signal such that the steering angle of the vehicle at a stop position immediately before the entry prohibited area in the changed unit path is substantially 0 degrees, when the entry detector has detected the entry into the entry prohibited area, and wherein the parking path planning unit is configured to calculate the unit path and the vehicle control signal on the basis of a performance value that is able to be output by an actuator of the vehicle at a time of automatic driving of the vehicle, characterized in that the parking path planning unit is configured to calculate a plurality of candidate unit paths in cases where the vehicle is moved within a range of upper and lower limit values of the performance value that is able to be output by the actuator of the vehicle at the time of automatic driving of the vehicle and to select a unit path which has the shortest distance from an arrival position of the unit path to the target parking position from the plurality of unit paths.