An image processing apparatus includes: an image processing unit configured to execute, in forming an image on both surfaces of a sheet, image processing including skew correction to deform the image in advance to offset distortion to be caused in the image to be formed on the sheet, wherein, the image processing unit receives specification of any of one side, two sides, and an external form of the sheet, as a reference position of the image processing for the image to be formed on the both surfaces of the sheet, and executes the image processing including the skew correction based on the specification.