A vehicle-mounted stereo camera device that achieves high-precision distance detection is provided. The provided vehicle-mounted stereo camera device includes a left camera and right camera disposed on a vehicle to cause a visual field of the left camera and a visual field of the right camera to overlap each other, a stereo processor that calculates a distance to a body outside the vehicle based on images captured by the left camera and right camera and on positions of the left camera and right camera on the vehicle, and sensors disposed near the left camera and right camera for detecting displacement amounts of the left camera and right camera. The stereo processor changes a cutout positions in the images captured by the left camera and right camera based on the displacement amounts.