A focus control apparatus and method capable of generating a focus position signal according to focus position error even in proximity to an interface between regions having different thicknesses, to perform a high precision focus position control using the focus position signal, are provided. A focus control apparatus includes an error signal correction portion configured to process a focus error signal that indicates an error of a focus position of an optical system with respect to an object. Moreover, the focus control apparatus includes a region conversion detection portion configured to output a region signal that corresponds to a first region or a second region of the object. The first and second regions of the object have different respective heights.