A constant velocity joint includes a first rotation body and a second rotation body. The first rotation body includes a cup unit, a shaft, and ribs that project from the cup unit and connect the cup unit to the shaft. One of the first rotation body and the second rotation body transmits a rotational driving force to other one of the first rotation body and the second rotation body through balls. The first rotation body is so formed that the cup unit and the shaft are formed into one piece using resin material. Moreover, the rib is so formed into one piece with the cup unit and the shaft using resin material.