An image processing apparatus capable of easily generating a two-dimensional panoramic image at a high speed from a plurality of three-dimensional images includes an acquisition unit configured to acquire a generation condition of a first en-face image generated from a first three-dimensional image of an target eye, a first generation unit configured to generate a second en-face image from a second three-dimensional image of the target eye by applying the generation condition acquired by the acquisition unit to the second three-dimensional image, and a second generation unit configured to generate a combined image by combining the first en-face image with the second en-face image.