A sheet container to contain a sheet includes a support unit including a plurality of engaged portions and supports the contained sheet, a moveable regulation unit that contacts a sheet end to regulate the sheet in position. The regulation unit includes an operating member held by a holding member and a fixing member movable with the operating member covered by a cover. The fixing member is movable between an engaging position at which the fixing member engages with one of the plurality of engaged portions and a non-engaged position at which the fixing member does not engage with one of the plurality of engaged portions. The operating member is engageable with the cover. The regulation unit is kept fixed to the support unit by the fixing member engaging with one of the plurality of engaged portions, with the cover engaging with the operating member.