An image display system, radiation imaging system, image display control program and image display control method, which make the position of an object of interest easier to perceive, are provided. A tomographic image generation section generates a tomographic image DG. A nipple height specification section specifies the height of a nipple P as measured from an imaging plane on the basis of the generated tomographic image DG. An image display control section controls displays at a display, via an interface section, such that an information image IG is displayed together with the generated tomographic image DG. The information image IG indicates the height of the nipple P and the slice height of the tomographic image DG that is being displayed.