The design of photoanode with highly efficient light harvesting and charge collection properties is important in photoelectrochemical (PEC) cell performance for hydrogen production. Here, we report the hierarchical In2O3:Sn/TiO2/CdS heterojunction nanowire array photoanode (ITO/TiO2/CdS-nanowire array photoanode) as it provides a short travel distance for charge carrier and long light absorption pathway by scattering effect. In addition, optical properties and device performance of the ITO/TiO2/CdS-nanowire array photoanode were compared with the TiO2 nanoparticle/CdS photoanode. The photocatalytic properties for water splitting were measured in the presence of sacrificial agent such as SO32− and S2− ions. Under illumination (AM 1.5G, 100 mW/cm2), ITO/TiO2/CdS-nanowire array photoanode exhibits a photocurrent density of 8.36 mA/cm2 at 0 V versus Ag/AgCl, which is four times higher than the TiO2 nanoparticle/CdS photoanode. The maximum applied bias photon-to-current efficiency for the ITO/TiO2/CdS-nanowire array and the TiO2 nanoparticle/CdS photoanode were 3.33% and 2.09%, respectively. The improved light harvesting and the charge collection properties due to the increased light absorption pathway and reduced electron travel distance by ITO nanowire lead to enhancement of PEC performance.