To provide a sheet processing device which includes a conveyance device capable of reversing a sheet by a simple configuration.

A sheet reversing device includes: a first conveyance part 39 which includes a first holder 39a for holding an end of a sheet and a supporting surface 39b for supporting the sheet, and which conveys the sheet having the one end held by the first holder and wholly supported by the supporting surface; a second conveyance part 33 which includes a second holder for holding the one end of the sheet, and which conveys the sheet; a third conveyance part 31b which includes a third holder 31bt for holding the other end of the sheet conveyed by the first conveyance part, which is swingably supported between a reception position to receive the sheet from the first conveyance part and a transfer position to transfer the sheet to the second conveyance part, and which conveys the sheet held by the third holder; and a sheet presser member 207 which is provided in the third conveyance part, and which presses the sheet, transferred to the first conveyance part from the third conveyance part, against the supporting surface of the first conveyance part.