A rolling bearing device includes a bearing portion and an oil supply unit provided adjacent, in the axial direction, to an annular space between an inner ring and an outer ring of the bearing portion to supply lubricating oil to the annular space. The oil supply unit includes an oil chamber that accommodates lubricating oil, a nozzle that discharges lubricating oil in the oil chamber, a pump body that applies a discharge force for causing lubricating oil in the oil chamber to fly from the nozzle toward the annular space, and a detection portion that detects gathering of lubricating oil at a discharge port of the nozzle. The detection portion includes a pair of electrodes disposed with the discharge port of the nozzle interposed therebetween, and a measurement portion that measures the capacitance of the pair of electrodes.