Disclosed is a sheet processing apparatus which includes: a supporting portion in which a sheet which has been conveyed is stacked; a pushing member configured to push the sheet with an abutting portion of the pushing member in order to fold the sheet supported on the supporting portion; and a setting portion configured to set a pushing position at which the pushing member pushes the sheet with a score to a position at which the sheet is to be folded at the score, wherein a center of the abutting portion does not coincides with a center of the score of the sheet.