Provided is a curable composition including oxide particles that include at least indium and tin, and to which a ligand having a hydrocarbon group and a binding site to the oxide particles is bonded; and a polymerizable compound, in which a content of the oxide particles in the composition is 18 mass % or more with respect to a total solid content of the composition; and a cured product of the curable composition or a lens unit including the cured product.