A paper ejection device holds paper ejected out from an upstream device through a paper-ejection opening of the upstream device. The paper ejection device includes: a pair of side fences arranged parallel and perpendicularly to a paper ejection direction, the paper ejection direction being a direction in which paper is ejected through the paper-ejection opening, to restrict positions of edges of the ejected paper in a width direction; and a control unit that, when an ejection speed at which the paper is ejected through the paper-ejection opening is higher than a predetermined speed, controls spacing between the pair of side fences to be narrower than spacing between the pair of side fences for paper ejected at a speed equal to or lower than the predetermined speed.