A sheet loading apparatus includes: a sheet loading portion that includes a bottom portion on which a sheet is loaded; and a regulating mechanism that butts an end edge of the sheet extending in a first direction to limit a position of the sheet in a second direction. The regulating mechanism includes: a guide portion that is formed on the bottom portion to extend in the second direction; and a limiting member slidable along the guide portion. The guide portion includes: first engaged portions that are formed at predetermined intervals along the second direction; and a second engaged portion that is formed continuously along the second direction. The limiting member includes: a pair of engaging portions that are composed of: a first engagement portion able to engage with one of the first engaged portions; and a second engagement portion which engages with the second engaged portion.