In the present study, visible and UV-A light induced photocatalysis of aqueous solutions of formic and oxalic acid with S-doped, Fe-loaded TiO2 (SFT) was investigated. The effect of formic and oxalic acid concentrations (50 and 100 mg/L), initial pH (3 and 7) and catalyst concentrations (5 and 10 g/L) under visible or UV-A light on degradation rate was evaluated. The removal efficiencies of formic acid and oxalic solutions (50 mg/L) under UV light irradiation with SFT were 10% and 67%, respectively. During the experimental run conducted with formic acid solutions (50 mg/L), 53 and 40% dissolved organic carbon (DOC) removal efficiencies were achieved for 5 and 10 g/L catalyst concentrations at 120 min reaction time under visible light irradiation at pH 3.0, respectively. At the same experimental conditions the obtained DOC removal efficiencies for oxalic acid were 41% for 5 g/L and 51 % for 10 g/L catalyst concentration. The photocatalytic oxidation process under visible light was generally slower at pH 7 than at pH 3. Increasing the photocatalyst concentration from 5 to 10 g/L increased oxalic acid degradation rate, but decreased formic acid degradation under visible light irradiation. Our experimental results have clearly indicated that SFT has a potential as a photocatalyst that can be activated via visible light irradiation for the photocatalytic mineralization of the studied model pollutants.