Iron pyrite (FeS2) thin films have been deposited onto indium doped tin oxide coated glass substrate using two sulphur anion sources such as thiourea [(NH2)2CS] and sodium thiosulfate [Na2S2O3] by electrochemical deposition method. The profilometer analysis shows that roughness of FeS2 thin films obtained low for (NH2)2CS than the Na2S2O3 as an anion sources. The X-ray diffraction analysis confirms that as-deposited FeS2 thin films shows cubic system with (200) plane preferential orientation for using (NH2)2CS. When Na2S2O3 is used it results in a cubic system (200) along with hexagonal (201) of FeS reflection peak signifying a mixed phase. The optical studies of the thin films deposited using (NH2)2CS shows the bandgap at 0.98 eV, while the bandgap for Na2S2O3 was 0.92 V. Atomic force microscopy images shows a crack free and densely packed morphology of FeS2 thin films obtained for both anion sources. The electrochemical impedance spectra study of FeS2 thin film exposed that less of charge transfer resistance and fine conductivity was obtained from the (NH2)2CS than Na2S2O3 as a sulfur source. The photocurrent study of as-deposited thin films shows that a significant by enhanced photocurrent response for (NH2)2CS compared to Na2S2O3 used thin films. The electrocatalytic activity of as deposited FeS2 thin films shows that better I−/I3− redox couple when investigated by the cyclic voltammetry. The as-deposited FeS2 thin films obtained from the (NH2)2CS as an anion source is capable of to substituting the for platinum electrode.