A sheet processing apparatus includes a conveying portion, a stack portion on which sheets conveyed by the conveying portion are stacked, a first regulating portion regulating a position of a sheet bundle stacked on the stack portion in a crossing direction, a second regulating portion regulating a position of a sheet bundle on the stack portion in a conveying direction, a first binding device moved in the crossing direction and binding a corner portion of a sheet bundle by a staple, a second binding device binding a corner portion of a sheet bundle without a staple, and a controller positioning the first binding device and binding a corner portion of a sheet bundle by the first binding device. The controller also moves the second binding device and binds a corner portion of a sheet bundle without a staple by the second binding device.
