A sheet conveyance unit includes first and second conveyance rollers facing each other, a first stopper provided at an axial end portion of the first conveyance roller, projecting radially beyond a circumferential surface of the first conveyance roller, downstream rollers positioned downstream from the first and second conveyance rollers in a sheet conveyance direction, an engaging and disengaging unit to disengage the first and second conveyance rollers from each other, and a controller. The first stopper rotates to a contact position projecting into the sheet conveyance path and to a non-contact position away from the sheet conveyance path as the first conveyance roller rotates. The first stopper moves to the non-contact position after stopping a sheet. The first and second conveyance rollers are disengaged from each other after a leading end of the sheet reaches the downstream rollers, before the first stopper moves to the contact position.