A throttle control apparatus serves to control a degree of opening of a throttle valve via an actuator. The throttle valve is provided in an air induction passage of an internal combustion engine. The throttle control apparatus includes a throttle opening degree sensor for detecting the degree of opening of the throttle valve. An engine operating condition detecting device is operative to detect an operating condition of the engine. A throttle opening degree estimating device is operative to estimate the degree of opening of the throttle valve on the basis of the operating condition of the engine which is detected by the engine operating condition detecting device. A memorizing means serves to memorize a corrective quantity. A corrective quantity updating device is operative to update the corrective quantity memorized by the memorizing device on the basis of a difference between an output value from the throttle opening degree sensor and an estimated value from the throttle opening degree estimating device. A control device serves to adjust a controlled quantity of the actuator in response to the output value from the throttle opening degree sensor and the corrective quantity memorized by the memorizing device to control the degree of opening of the throttle valve.