A bearing device for a wheel is capable of suppressing a backlash in a circumferential direction, is excellent in coupling operability of a hub wheel and an outer joint member of a constant velocity universal joint, and is excellent for maintenance by allowing separation of the hub wheel and the outer joint member of the constant velocity universal joint. In the bearing device for a wheel, a hub wheel, a double-row roller bearing, and a constant velocity universal joint are unitized together, and the hub wheel and a shaft section of an outer joint member of the constant velocity universal joint are separably coupled with each other through intermediation of a recess-projection fitting structure, the shaft section being inserted in a fitting manner into a hole portion of the hub wheel.