The present technology relates to a positioning device, a communication device, and a positioning system that are designed to consume lower amounts of power in a more reliable manner. In a case where the identification information included in a received radio signal is the identification information about the current search target, and the reception intensity of the radio signal exceeds a predetermined value, the positioning device transmits a distance measurement start instruction to the communication device, and carries out measurement of the distance to the communication device. Upon receiving the distance measurement start instruction from the positioning device, the communication device performs measurement of the distance to the positioning device. The present technology can be applied to a positioning system.