A sensor control device, and a gas sensor and sensor control device for applying a voltage to a sensor element of the gas sensor including an oxygen ion conductor and a pair of electrodes formed on the oxygen ion conductor of the gas sensor. The sensor control device includes a potential output terminal electrically connected to one of the pair of electrodes and a potential reference terminal electrically connected to the other of the pair of electrodes constituting the sensor element. The sensor control device applies a target voltage to the sensor element via the potential output terminal, corrected to take into account variation in the potential of the potential reference terminal.