An image forming apparatus includes a fixing portion that fixes a toner image to a sheet by applying heat to the sheet, a conveyance path through which back and forth conveyance of the sheet conveyed from the fixing portion is performed by normally and reversely rotating a conveying roller, and a water addition portion that adds water to the sheet at a water addition position in the conveyance path on upstream in a conveying direction of the conveying roller. In addition, a controller controls the water addition portion such that the water is added to the sheet conveyed from the fixing portion to the water addition position, and the water is added to the sheet to which the reverse conveyance has been performed after an upstream end in the conveying direction of the sheet passes through the water addition position.