There is provided a wheel support bearing assembly which includes an outer member (1) having an inner peripheral surface formed with outer raceways (4), an inner member (2) having inner raceways (5) aligned with the respective outer raceways (4), and rows of rolling elements (3). The inner member (2) includes a hub axle (2A) and a raceway forming member (2B) mounted on an inboard end of the hub axle (2A). The inner raceways (5) are formed on an outer peripheral surface of the hub axle (2A) and an outer peripheral surface of the raceway forming member (2B), respectively. The bearing assembly also includes a ring-shaped to-be-detected element (9) mounted on a portion of the inner member (2) between the inner raceways (5) and having an outer diameter smaller than the diameter of the circle inscribed by the row of the rolling elements (3), and a sensor (10), for detecting the element (9), mounted on a corresponding portion of the outer member (1) between the outer raceways (4).