Provided is an object detection device that makes it possible to more accurately detect a road surface even when an area that is not the road surface occupies the majority of an image and the gradient of the road surface is large, and to detect an obstacle on a road surface with greater accuracy than in the prior art. The object detection device includes: a parallax calculation unit that generates a parallax image on the basis of a plurality of images; a parallax gradient calculation unit that, for each pixel in the parallax image, calculates a parallax gradient for each pixel on the basis of the parallax of a predetermined pixel and a pixel that is adjacent to the predetermined pixel; a detection candidate determination unit that determines whether a detection candidate is present on the basis of the parallax gradient of each pixel; a voting unit that carries out a histogram vote using each of the pixels that are determined to be detection candidates and generates a histogram frequency for each of the pixels when the detection candidate is determined to be present; and an object detection unit that detects presence of an object and a position of the object on the basis of the histogram frequency.