A fixing device including a heated endless belt, a first member, a second member, a pressure roller, a guide member, a sliding member, and a lubricant application member. The first member is a non-rotating body inside of the belt and together with the second member tensions the belt. The pressure roller is outside the belt and presses against the first member via the belt, thereby forming the fixing nip. The guide member is inside of the belt and has a guide surface that guides the belt in circulation and a recess opening into the guide surface. The sliding member is between the belt and the first member. The lubricant application member is fitted in the recess and applies lubricant to the belt. The guide surface has an arc shape that is interrupted by the recess in a cross section perpendicular to an axis of rotation of the pressure roller.