A sheet storage apparatus for storing sheets including a sheet storage unit including a lower guide configured to guide a lower surface of the conveyed sheet, an upper guide configured to guide an upper surface of the conveyed sheet, and a shutting-off unit provided in one of the lower guide and the upper guide, configured to be movable around a rotational axis and between a shutting-off position at which a downstream end of the conveying direction of the sheet stored in the sheet storage unit is shut off and a retracting position for retracting from the shutting-off position, and a plurality of stages of sheet storage units is vertically stacked and at least a part of the shutting-off unit overlaps the rotational axis of the adjacent sheet storage unit in a vertical direction at the shutting-off position.