A toner for developing an electrostatic charge image contains toner particles containing at least one binder resin; the Mg element in an amount such that the net intensity of x-ray fluorescence from the Mg element in the toner is 0.10 kcps or more and 1.20 kcps or less; and external additives including particles of at least one compound represented by formula (1) and particles of a metal salt of a fatty acid, MTiO3   (1) where M represents at least one selected from the group consisting of Ca, Sr, and Ba.