Mn-, Ru-, Rh-, and Ir-doped SrTiO3 possessed intense absorption bands in the visible light region due to excitation from the discontinuous levels formed by the dopants to the conduction band of the SrTiO3 host. Mn- and Ru-doped SrTiO3 showed photocatalytic activities for O-2 evolution from an aqueous silver nitrate solution while Ru-, Rh-, and Ir-doped SrTiO3 loaded with Pt cocatalysts produced H-2 from an aqueous methanol solution under visible light irradiation (lambda > 440 nm). The Rh(1%)-doped SrTiO3 photocatalyst loaded with a Pt cocatalyst (0.1 wt %) gave 5.2% of the quantum yield at 420 nm for the H-2 evolution reaction.