A sheet processing apparatus includes a carry-in path for guiding a sheet from a carry-in entrance, a shift roller provided in the carry-in path to relay and transport the sheet, a first transport path positioned on the downstream side of the relay roller to transport the sheet from the carry-in path to a first collection tray, and a second transport path branched off from the carry-in path to transport the transported sheet to a second collection tray. The relay roller shifts the sheet in the direction crossing the transport direction, while the shift by the relay roller is performed after the sheet front end enters the first transport path or second transport path. Thus, it is possible to provide a relatively compact sheet processing apparatus capable of shifting in sorting and shifting sheets, without increasing the carry-in path.