A sheet transport device includes a transport unit, a load section, and a sheet accommodation section. The transport unit has a transport path along which a sheet read at a read position is transported to an output unit. The sheet output by the output unit is loaded onto the load section. The sheet accommodation section is disposed downstream in an output direction of the sheet from an inner wall surface extending upward adjacent to the load section and has a recess capable of accommodating a sheet of a predetermined minimum size. A retrieval space through which the sheet accommodated in the sheet accommodation section is retrievable is provided by exposing the transport path in a direction opposite to a loading direction of the sheet.