An approaching vehicle detecting system that detects an approaching vehicle on the basis of sounds collected by a plurality of sound collectors mounted on a host vehicle determines whether a transverse moving direction of a sound source detected by the plurality of sound collectors is a direction approaching the host vehicle, determines whether a vertical position of the sound source detected using the plurality of sound collectors is in the same plane as that of the host vehicle, and detects that sound source as the approaching vehicle when it is determined that the transverse moving direction of the sound source is the direction approaching the host vehicle and the vertical position of the sound source is in the same plane as that of the host vehicle.