A heating device includes a belt member, plural heating elements, and plural resistance elements. The belt member is rotated. The plural heating elements are arranged in a width direction of the belt member and generate heat so as to heat the belt member. The plural resistance elements having positive temperature coefficients are each connected in series with a corresponding one of the plural heating elements. In the heating device, a temperature of the belt member is reduced by an increase in resistances of the plural resistance elements caused by an increase in temperatures of the plural resistance elements.