A vehicular brake hydraulic pressure controller has a reference hydraulic pressure acquisition section 21a for acquiring hydraulic pressure achieved on the other side of an electromagnetic valve as reference hydraulic pressure, a differential pressure calculation section 21b for calculating a differential pressure Py by subtracting previously-estimated hydraulic pressure achieved on one side of the electromagnetic valve from the reference hydraulic pressure; a pressure gradient coefficient calculation section 21c for acquiring a pressure gradient coefficient K correlating with a drive current of the electromagnetic valve and the differential pressure Py, and an estimated hydraulic pressure calculation section 21e for estimating current hydraulic pressure by adding a product, which has been produced by multiplying the differential pressure Py by the pressure gradient coefficient K, to the previously-estimated hydraulic pressure achieved on one side of the electromagnetic valve.