A sheet ejector is provided that includes an ejection roller unit including a first roller and a second roller, a pushing member that rotates concentrically with the first roller and includes a projection formed on a circumferential surface thereof, the projection contacting a trailing end of a sheet to be ejected and pushing out the sheet in an ejecting direction, and a contact member including a contact portion disposed, in a view along a rotational-axis direction of the first roller, in such a position as to overlap or be downstream relative to a most downstream position of a rotational trajectory of the pushing member in the ejecting direction, the contact portion configured to extend up to a position closer to the second roller than the rotational axis of the first roller and contact the trailing end of the sheet ejected from the ejection roller unit.