A vehicle door structure includes a sliding door configured to open and close a door opening formed in a side portion of a vehicle body, and a slide supporting mechanism configured to slide the sliding door. The slide supporting mechanism includes a middle slide rail disposed so as to extend in an opening-and-closing direction of the sliding door, and a guide body that is guided by the middle slide rail. The guide body includes two first rollers, two second rollers, a body portion, and an arm portion. The body portion rotatably supports the two first rollers and the two second rollers. The arm portion couples the sliding door and the body portion. The arm portion is disposed, on at least one of the sliding door and the body portion, to be turnable around a shaft parallel to rotary axes of the first rollers.