A fixing device includes a fixing member, a heating member provided inside the fixing member to heat the fixing member, a nip formation member provided inside the fixing member and supported by the heating member, and a pressing member pressed against the nip formation member via the fixing member to form a fixing nip between the fixing member and the pressing member through which a recording medium bearing a toner image passes. The nip formation member includes a convex portion provided at a center of the nip formation member in an axial direction of the fixing member and protruding toward the heating member. The heating member has a tapered shape corresponding to the convex portion of the nip formation member, in which the heating member is tapered from lateral ends toward a center of the heating member in the axial direction of the fixing member.