A resin composition is provided including: coated particles, each including a core containing a metal oxide and a coating layer containing an aluminum hydrous oxide and provided on a surface of the core; and a resin. The metal oxide is represented by MxOy, where M represents at least one element selected from the group consisting of Ba, Ti, Sr, Pb, Zr, La, Ta, Ca, and Bi, and x and y each represent a number determined from a stoichiometric ratio according to the valence of the metal element M. The resin composition has an atomic ratio Al/(M+Al) of 0.05 or more and 0.7 or less, as determined by XPS for the particles contained in the resin composition.