A fixing device includes a pressing member that is rotatably held and provides a pressure acting in one direction; a heating member that is rotatably held, faces the pressing member, and includes a substantially cylindrical member and a heating unit, the substantially cylindrical member receiving the pressure, the heating unit being provided inside the substantially cylindrical member, the heating member fixing a toner image on a sheet with the pressure and heat; a drive source that outputs a driving force with which the heating member is rotated; and a transmission member having a space that receives an end of the substantially cylindrical member with a gap interposed therebetween, the transmission member having an inner circumferential surface that comes into contact with the end of the substantially cylindrical member in the space when the substantially cylindrical member receives the pressure, the transmission member transmitting the driving force to the heating member.