1. An image display apparatus configured to display an image based on an input image signal, the image display apparatus comprising: an image signal processing unit configured to adjust a display image based on an adjustment parameter; a control unit configured to generate a plurality of adjustment parameter candidates different from each other; a display unit configured to display a list of a plurality of adjusted images adjusted by the image signal processing unit based on the plurality of adjustment parameter candidates; and a user operation input unit configured to make a user to select an adjusted image from among the plurality of adjusted images displayed as a list, wherein the control unit: repeats processing for causing the display unit to display the list of the plurality of adjusted images, and generating the adjustment parameter candidate, based on an adjusted image selected by the user and the plurality of adjustment parameter candidates; and sets, in a case where a same adjusted image is selected, the adjustment parameter candidate set to the selected adjusted image, as the adjustment parameter when displaying an image.