A decurling device includes: a first transport unit including a transport roller, the first transport unit that sandwiches a transported sheet and transports the transported sheet further downstream; and a second transport unit including an endless belt that is in contact with the transport roller. The transport roller has an elasticity that, when the belt is pressed against the transport roller, allows the belt to bite into the transport roller by a bite amount corresponding to a pressing force, the second transport unit includes an abutting member disposed inside the belt, the abutting member pressing the belt from an inside of the belt and causing the belt to abut against the transport roller, and a guide member, the abutting member includes an upstream protrusion, an downstream protrusion, the upstream protrusion and the downstream protrusion being provided at positions away from each other at an upstream portion and a downstream portion in a sheet transport direction, each of the upstream protrusion and the downstream protrusion protruding toward an inner surface of the belt, and a recess provided in an intermediate portion between the upstream protrusion and the downstream protrusion in the sheet transport direction, the recess being recessed away from a straight line connecting a top portion of the upstream protrusion and a top portion of the downstream protrusion, the guide member includes a contact surface that is in contact with the inner surface of the belt, the contact surface defining a part of a circulation track of the belt, and the upstream protrusion protrudes beyond a virtual circle that is tangent to the contact surface.