Disclosed are an apparatus and a method for estimating a distance and a position between a photographing unit and a predetermined object based on an image of the photographing unit using a single camera. An apparatus for estimating a distance of an object based on a single camera image includes: a region detector detecting an object region box including the predetermined object in an image photographed by a photographing unit; a distance estimator measuring the size of the detected object region box and estimating a distance between the predetermined object and the photographing unit on the basis of an interpolating function interpolating the relationship of the size of the object region box and distances up to the photographing unit and the predetermined object; and a position estimator generating object position information estimating the position of the predetermined object.