1. An object detection device comprising: an imaging unit carried on a movable body; a first calculation unit that calculate an observed value of an image displacement among a plurality of images captured by the imaging unit at respective different timings; a first object detection unit that detects an object candidate and acquires information of the object candidate; a second calculation unit that calculates a theoretic value of the image displacement on the basis of the information of the object candidate; and a second object detection unit that compares the observed value of the image displacement and the theoretic value of the image displacement and determines whether the object candidate is an object on the basis of the comparison result.