A wiring guide of a vehicle door includes: an outside guide slidably disposed on one of a vehicle body and a door of a vehicle, and having an inner portion which has a hollow and circular arc shape; and an inside guide slidably disposed on the other side of the vehicle body and the vehicle door, having an inner portion which has a hollow and circular arc shape, slidably disposed in the inner portion of the outside guide, and having a wiring penetrating therein. The outside guide and the inside guide expand and shrink in a circular arc shape upon opening and closing of the door.