A controller executes a mode in an image forming apparatus in which an image is formed on a sheet by an image forming portion even if a sheet size included in an image forming job is inconsistent with a sheet size stored in the storage portion. In such a mode, the controller executes an operation by which an image having an orientation corresponding to a sheet orientation stored in the storage portion is formed on the sheet if a sheet orientation included in the image forming job is inconsistent with the sheet orientation stored in the storage portion.