A distance measurement system includes a pair of cameras and is arranged on a roof of a mobile object or an upper edge portion of a door of the mobile object. One of the cameras is arranged at a first portion on an upper surface of the roof or on the upper edge portion of the door, includes an optical axis oriented upward from the upper surface, and has a field of view in all directions around the optical axis. The other camera is arranged at a second portion different from the first portion on the upper surface of the roof or the upper edge portion of the door, includes an optical axis oriented upward from the upper surface, and has a field of view in all directions around the optical axis. Distance measurement in all directions from the mobile object is performed by using this pair of cameras.