To provide a bearing device for a wheel, in which a preload control is easy and a uniform amount of preload can be applied with a bearing seal being mounted, the bearing device for the wheel includes an outer member, an inner member and double rows of rolling elements interposed between the outer member and the inner member. The outer member has a flange on an outer periphery thereof and also has an inner periphery formed with two rolling surfaces. The inner member is formed with rolling surfaces opposed to the rolling surfaces of the outer member. The double rows of the rolling elements are interposed between the rolling surfaces of the outer member and the inner member. A sensor for detecting the amount of preload of the bearing is provided in one of the outer and inner members.