A bearing device includes: a bearing portion that has an inner ring, an outer ring, a plurality of balls interposed between the inner ring and the outer ring, and a cage that holds the balls; and an oil supply unit provided adjacent to the bearing portion in the axial direction. The oil supply unit has a pump that discharges a minute amount of lubricating oil to the bearing portion, and varies the amount of oil supplied to the bearing portion by discharge of lubricating oil from the pump.