WIRING HARNESS ROUTING STRUCTURE, LINK TYPE SLIDING DOOR, AND WIRING HARNESS

A wiring harness routing structure includes at least a sub-link arm and a routed line. The sub-link arm includes one end that is rotatably coupled to a vehicle body by using a first coupler, and another end that is rotatably coupled to a door body by using a second coupler, and slidably supports the door body relative to the vehicle body, while rotationally moving relative to each of the vehicle body and the door body. A routed line is routed and provided along the sub-link arm, and connects a vehicle-body-side connector and a door-side connector. In addition, the routed line is routed through a lower side in a height direction of the first coupler that is coupled to the sub-link arm, in a state where the door body has slid to be fully opened.