A calibration apparatus for a rotational angle measuring system includes a measuring system shaft and a measuring system housing. The calibration apparatus includes a shaft holding device which, in a calibration position, rotates about an axis of rotation and is co-rotatably connected to the measuring system shaft, and, in a load position, is decoupled from the measuring system shaft, a rotationally static housing holding device which, in the calibration position, is co-rotatably connected to the measuring system housing, and, in the load position, is decoupled from the measuring system housing, and a drive motor which drives the shaft holding device. In the calibration position, the shaft holding device has clamping jaws which are pressable onto the radial outer side of the measuring system shaft, and/or, the rotationally static housing holding apparatus has movable pistons which are pressable onto the radial outer side of the measuring system housing.