To provide a wire harness supporting device to be externally equipped on a wire harness stretched between a car body and a movable member, wherein the number of component items constituting the supporting device reduced, and the assembly work efficiency is improved.

The wire harness supporting device for supporting a wire harness stretched between a car body and a movable member movably connected to the car body has: a rotary cylindrical member which is rotatably mounted on the car body and/or the movable member; and a slide cylindrical member with both ends thereof opened which is slidably mounted orthogonal to the axis of rotation of the rotary cylindrical member and turned together with the rotary cylindrical member while arranging the wire harness through hollow parts of the rotary cylindrical member and the slide cylindrical member. According to the movement of the wire harness, the slide cylindrical member slides orthogonal to the axis of rotation of the rotary cylindrical member, and turned around the axis of rotation of the rotary cylindrical member. The rotary cylindrical member is turned together with the turn of the slide cylindrical member to follow the wire harness.