A sheet bonding apparatus includes an applying portion, a fixing portion, a folding portion, and a bonding portion including a heating member and a non-heating member which oppose to each other and which are for bonding the sheet by nipping the sheet therebetween. Two regions opposing to each other when the folding portion folds a sheet are a first region and a second region. In a case that when the bonding portion bonds the folded sheet, the first region is positioned on a heating member side and the second region is positioned on a non-heating member side, the applying portion applies the powdery adhesive so that an application amount of the powdery adhesive on the sheet is smaller in the first region than in the second region.