An object detection device includes a map generator configured to generate, based on a distance image that includes distance information for each coordinate, a first map in which the coordinate in a horizontal direction of the distance image is associated with the distance information, and a second map in which the coordinate in the horizontal direction of the distance image is associated with the distance information, the second map having a lower resolution than the first map; and an object detector configured to detect an object based on the first map when a distance represented by the distance information is within a first range, and to detect an object based on the second map when a distance represented by the distance information is within a second range.