A facile one-step hydrothermal method was developed to prepare TiO2/reduced graphene oxide (TiO2/RGO) composite, which contains TiO2 microspheres and two-dimensional RGO with dispersed TiO2 nanoparticles. During the hydrothermal process, reduction of graphene oxide (GO) and hydrolysis of the titanium source were both obtained. Highly electronically conductive RGO was incorporated into TiO2 photoanodes of dye-sensitized solar cells (DSSCs), which facilitated a faster electron transfer efficiency and a lower reduction in electron recombination, together with enhanced light scattering and dye adsorption. The performance measurement of the DSSCs showed that incorporation of RGO can significantly improve the photovoltaic performance of DSSCs; the short-circuit current density showed a 45.5% increase and a total conversion efficiency of 7.57% was obtained.