A sheet processing apparatus includes a pressing unit including a first pressing member and a second pressing member. The pressing unit is configured to sandwich and press a fold part of a folded sheet bundle between the first pressing member and the second pressing member. The sheet processing apparatus also includes a moving unit configured to move a position pressed by the pressing unit in a direction of a fold of the sheet bundle. A position pressed by the first pressing member on the sheet bundle and another position pressed by the second pressing member on the sheet bundle are shifted with respect to each other in the direction of the fold of the sheet bundle.