A fixing device includes a rotary fixing member, a heater, a pressing member, a nip formation member, a reinforcement member, a sliding sheet, and a holding member. The nip formation member is disposed at an inner circumferential side of the fixing member and pressed by the pressing member via the fixing member to form a nipping portion. The reinforcement member is stationarily disposed in an internal diameter area of the fixing member to support the nip formation member. The sliding sheet is disposed between the nip formation member and an inner circumferential face of the fixing member. The holding member is disposed at a member differing from the nip formation member to hold the sliding sheet in a state in which the sliding sheet is in close contact with a nipping face of the nip formation member facing the nipping portion.