An image-pickup apparatus includes an image-pickup element including a plurality of image-pickup pixels configured to photoelectrically convert light from an image-pickup lens and to generate an image of an object, and a plurality of focus detection pixels each configured to receive light which has passed through an area of a part of an exit pupil of the image-pickup lens, a flicker correction value generator configured to generate a flicker correction value for correcting a flicker in an image signal output from the image-pickup pixels, and a flicker corrector configured to correct a flicker in a focus detection signal output from the focus detection pixels based on the flicker correction value.