A sensor calibration apparatus for calibrating a sensor mounted to a vehicle is provided. The sensor calibration apparatus includes a projection instruction unit that causes a projection device, which is mounted to the vehicle and projects light, to project an optical image representing a calibration marker onto a detection range of the sensor, an optical image information acquisition unit that acquires optical image information detected by the sensor, and a calculation unit that calculates a calibration value of the sensor based on the optical image information.